83 results on '"Fonseca RG"'
Search Results
2. Effect of Simulated Annual At-home Bleaching on Susceptibility to Staining, Translucency, and Whiteness Variations of Computer-aided Design and Computer-aided Manufacturing Monolithic Materials
- Author
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Ramos, AC, primary, Peña, RC, additional, Dovigo, LN, additional, Pérez, MM, additional, and Fonseca, RG, additional
- Published
- 2023
- Full Text
- View/download PDF
3. Effect of Successive In-office Bleaching Sessions on the Surface Properties, Substance Loss, Biaxial Flexural Strength, and Reliability of CAD-CAM Monolithic Materials
- Author
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Queiroz, JFC, primary, Fernandes, L, additional, Dovigo, LN, additional, and Fonseca, RG, additional
- Published
- 2022
- Full Text
- View/download PDF
4. Effect of In-office Bleaching on Color, Translucency, and Whiteness Variations in CAD-CAM Monolithic Materials
- Author
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Fonseca, RG, primary, Peńa, RC, additional, Simóes, R, additional, Ramos, AC, additional, and Dovigo, LN, additional
- Published
- 2021
- Full Text
- View/download PDF
5. Efficacy of surface treatments on the bond strength of resin cements to two brands of zirconia ceramic
- Author
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Baldissara, P, Querzè, M, Monaco, C, Scotti, R, Fonseca, Rg., Baldissara P, Querzè M, Monaco C, Scotti R, and Fonseca RG.
- Subjects
Time Factors ,all-ceramic crown ,Surface Properties ,all-ceramic crowns ,Dental Cements ,Composite Resins ,zirconia ,luting cements ,adhesion ,luting cement ,Dental Materials ,Materials Testing ,Aluminum Oxide ,Humans ,Yttrium ,Dental Bonding ,Temperature ,Adhesiveness ,Humidity ,Silicon Dioxide ,Resin Cements ,Dental Etching ,Microscopy, Electron, Scanning ,Methacrylates ,Aluminum Silicates ,Glass ,Stress, Mechanical ,Zirconium ,Shear Strength - Abstract
Purpose: To compare the shear bond strengths (SBS) of two cements to two Y-TZP ceramics subjected to different surface treatments. Materials and Methods: Zirconia specimens were made from Lava (n = 36) and IPS e.max ZirCAD (n = 36), and their surfaces were treated as follows: no treatment (control), silica coating with 30-µm silica-modified alumina (Al2O3) particles (CoJet Sand), or coating with liners Lava Ceram for Lava and Intensive ZirLiner for IPS e.max ZirCAD. Composite resin cylinders were bonded to zirconia with Panavia F or RelyX Unicem resin cements. All specimens were thermocycled (6000 cycles at 5°C/55°C) and subjected to SBS testing. Data were analyzed by three-way ANOVA and Tukey's (HSD) post-hoc test (α = 0.05). Failure mode was analyzed by stereomicroscope and SEM. Results: CoJet Sand and liners promoted significantly higher SBS than their control groups, but had similar results to one another. Panavia F provided significantly higher SBS values than RelyX Unicem (p < 0.01) for nontreated zirconia specimens of both brands. When Lava and IPS e.max ZirCAD were abraded with CoJet Sand, RelyX Unicem promoted significantly higher SBS values than Panavia F (p < 0.001). There was no significant difference between the two cements when the zirconia specimens were treated with their respective liners. The nontreated specimens and those treated with CoJet Sand exhibited a high percentage of adhesive and mixed A failures, while the specimens treated with liners presented an increase in mixed A and mixed C failures as well as some cohesive failure in the bulk of Lava Ceram for both cements. Conclusion: CoJet Sand and liners provided the best surface treatment for Lava and IPS e.max ZirCAD. The best surface treatment/cement combinations were CoJet Sand/RelyX Unicem and liner/Panavia F. SBS of Panavia F and RelyX Unicem was not influenced by the zirconia brand.
- Published
- 2013
6. Air Abrasion Before and/or After Zirconia Sintering: Surface Characterization, Flexural Strength, and Resin Cement Bond Strength
- Author
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Abi-Rached, FO, primary, Martins, SB, primary, Almeida-Júnior, AA, primary, Adabo, GL, primary, Góes, M Sousa, primary, and Fonseca, RG, primary
- Published
- 2015
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7. Shear Bond Strength of Different Repair Systems to Titanium After Water Aging
- Author
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Haneda, IG, primary, Fonseca, RG, primary, Abi-Rached, FO, primary, Adabo, GL, primary, and Cruz, CAS, primary
- Published
- 2012
- Full Text
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8. Shear bond strength of metal-ceramic repair systems.
- Author
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Haneda IG, Fonseca RG, de Almeida JGS, dos Santos Cruz CAS, and Adabo GL
- Abstract
This study evaluated the shear bond strength of different repair systems to nickel-chromium (NiCr) alloy after storage in water for either 24 hours or six months. One hundred cylindrical specimens (3 mm thick x 9 mm diameter) were fabricated using an NiCr alloy and embedded in a PVC ring, where they received one of five bonding and resin composite repair treatments (n = 20): Clearfil SE Bond/Clearfil AP-X (Group 1), Bistite II DC/Palfique (Group 2), CoJet/Z100 (Group 3), Scotchbond Multi-Purpose Plus/Z100 (Group 4; reference group), and CoJet Sand plus Scotchbond Multi-Purpose Plus/Z100 (Group 5). The specimens were stored in distilled water for 24 hours at 37°C, thermocycled for 1,000 cycles in two baths (at 5°C and 55°C) with a dwell time of 30 seconds for each bath, and stored in distilled water at 37°C for either 24 hours or six months.At 24 hours, Group 3 presented the highest mean values (P < 0.001); at six months, Group 5 demonstrated the highest mean values (P < 0.001). At six months, Group 5 presented a significant increase in shear bond strength (P < 0.001), while Groups 1 and 3 showed a significant reduction (P < 0.001). There were no significant differences between the storage times for Group 2 (P = 0.064) or Group 4 (P = 0.490). [ABSTRACT FROM AUTHOR]
- Published
- 2009
9. Diametral tensile strength of dual-curing resin cements submitted exclusively to autopolymerization.
- Author
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Fonseca RG, Artusi TP, dos Santos JG, and Adabo GL
- Abstract
OBJECTIVES: To evaluate, at different times, the diametral tensile strength (DTS) of dual-curing resin cements that were not photopolymerized. METHOD AND MATERIALS: Equal amounts of base and catalyst pastes of Panavia F (Kuraray), Variolink II (Vivadent), Rely X (3M ESPE), and Enforce (Dentsply) were mixed and inserted into cylindrical molds (4 x 2 mm) (n = 10). Cements were not photopolymerized. DTS test was performed in a testing machine at 30 minutes, 1 hour, 24 hours, and 7 days. The specimens were stored in light-proof containers with distilled water at 37 degrees C until the time of assay. An autopolymerizing resin cement (Cement-It, Jeneric Pentron) and a zinc phosphate cement served as controls. One-way analysis of variance (ANOVA) and Tukey test were performed separately for each cement and for each time (P <.05). RESULTS: All cements showed an increase in DTS when tested at 1 and 24 hours. Tests at 24 hours and 7 days revealed no statistically significant differences. In all groups, the zinc phosphate cement had the lowest DTS mean values (2.1 MPa, 3.6 MPa, 6.5 MPa, and 6.9 MPa), while Cement-It (35.1 MPa, 33.6 MPa, 46.9 MPa, and 46.3 MPa) and Enforce (31.9 MPa, 31.7 MPa, 43.4 MPa, and 47.6 MPa) presented the highest DTS mean values. CONCLUSION: All cements presented maximal strength at 24 hours. The dual-curing resin cements, even when nonphotopolymerized, demonstrated higher DTS than the zinc phosphate cement and similar or lower values than the autopolymerizing resin cement. [ABSTRACT FROM AUTHOR]
- Published
- 2007
10. Exploring the optical behavior and relative translucency parameter of CAD-CAM resin-based composites, polymer-infiltrated ceramic network, and feldspar porcelain.
- Author
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Mascaro BA, Tejada-Casado M, Fonseca RG, Reis JMDSN, and Pérez MM
- Subjects
- Potassium Compounds chemistry, Dental Porcelain chemistry, Polymers chemistry, Ceramics chemistry, Dental Materials chemistry, Computer-Aided Design, Materials Testing, Composite Resins chemistry, Aluminum Silicates chemistry
- Abstract
Objectives: To evaluate and compare the optical properties and relative translucency parameter of CAD-CAM restorative materials., Methods: Four CAD-CAM materials were evaluated: Lava Ultimate (LU), Grandio Blocs (GB), VITA Enamic (VE), and VITA Mark II (VM). Disk-shaped samples in shade A2-HT were prepared (n = 10) and polished to 1.00 ± 0.01 mm of thickness. Scattering (S), absorption (K), albedo (a) coefficient, transmittance (T%), light reflectivity (RI), infinite optical thickness (X
∞ ), and radiative transfer coefficients (μa , and μ'S ) were calculated using Kubelka-Munk method and Thennadil's semi-empirical approach. Root Mean Square Error (RMSE) and Goodness of Fit (GFC) were used as performance optical behavior. Translucency differences were evaluated using the relative translucency parameter (RTP00 ) and 50:50 % translucency perceptibility and acceptability thresholds (TPT00 and TAT00 )., Results: The spectral distribution of S, K, T%, RI, and X∞ was wavelength-dependent. GFC and RMSE values indicated good spectral behavior matches and good comparative spectral values for RI in LU-GB, LU-VE, and GB-VE, and for K in VE-VM. VM displayed the highest scattering values across the wavelengths, while VE and VM showed lower absorption at shorter wavelengths. LU and GB had the highest transmittance. The X∞ values indicated that all 1.0 mm thick materials could be influenced by the background. No good spectral match and no good comparative spectral values were found between CAD-CAM materials and anterior bovine maxillary specimens. VM had the lowest RTP00 values with perceptible and unacceptable differences compared to CAD-CAM materials evaluated., Significance: Understanding the optical behavior of different CAD-CAM materials was essential for guiding clinicians in material selection and optimizing their clinical performance. The findings confirm that the different compositions and microstructure impact the optical properties and translucency of CAD-CAM restorative materials., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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11. Effect of Successive At-home Bleaching Sessions on the Surface Properties, Biaxial Flexural Strength, and Reliability of CAD-CAM Monolithic Materials.
- Author
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Queiroz J, Amaro LF, Massucatto LO, Dovigo LN, Adabo GL, and Fonseca RG
- Subjects
- Reproducibility of Results, Tooth Bleaching Agents, Dental Materials chemistry, Peroxides, Humans, Hardness, Dental Porcelain chemistry, Ceramics, Surface Properties, Materials Testing, Tooth Bleaching methods, Flexural Strength, Computer-Aided Design, Carbamide Peroxide
- Abstract
Although at-home bleaching can recover the optical properties of stained CAD-CAM monolithic materials, little is known about its impact on their surface and mechanical properties, especially when successive sessions are performed. This study evaluated the effect of successive at-home bleaching sessions on the microhardness, roughness, topography, biaxial flexural strength (BFS), and reliability of CAD-CAM monolithic materials. Disks from Lava Ultimate (LU), Vita Enamic (VE), and IPS Empress CAD (EMP) were fabricated and submitted to up to three bleaching sessions. At-home bleaching was performed with 10% carbamide peroxide, and each session consisted of one application for 10 hours/day for 14 days. The analyses of the aforementioned parameters were assessed before and after the first, second, and third bleaching sessions, except for BFS, which was evaluated at baseline and after the third session. The Weibull modulus was calculated from the BFS data. The microhardness of the three materials as well as the roughness of LU were not affected by the sessions, whereas the roughness of VE and EMP increased from the second session. All materials displayed topographic changes, which became more pronounced with the increase in the number of sessions. Although bleaching decreased the BFS of the materials, it did not adversely affect their reliability. Successive at-home bleaching sessions with the protocol used in the present study cannot be considered a safe procedure for the materials evaluated., (©Operative Dentistry, 2024.)
- Published
- 2024
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12. Facile Synthesis of Highly Stretchable, Tough, and Photodegradable Hydrogels.
- Author
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Fonseca RG, Kuster A, Fernandes PP, Tavakoli M, Pereira P, Fernandes JR, De Bon F, Serra AC, Fonseca AC, and Coelho JFJ
- Subjects
- Humans, Alginates chemistry, Hydrophobic and Hydrophilic Interactions, Ions, Hydrogels chemistry, Polyethylene Glycols chemistry
- Abstract
Recently, highly stretchable and tough hydrogels that are photodegradable on-demand have been reported. Unfortunately, the preparation procedure is complex due to the hydrophobic nature of the photocrosslinkers. Herein, a simple method is reported to prepare photodegradable double-network (DN) hydrogels that exhibit high stretchability, toughness, and biocompatibility. Hydrophilic ortho-nitrobenzyl (ONB) crosslinkers incorporating different poly(ethylene glycol) (PEG) backbones (600, 1000, and 2000 g mol
-1 ) are synthesized. These photodegradable DN hydrogels are prepared by the irreversible crosslinking of chains by using such ONB crosslinkers, and the reversible ionic crosslinking between sodium alginate and divalent cations (Ca2+ ). Remarkable mechanical properties are obtained by combining ionic and covalent crosslinking and their synergistic effect, and by reducing the length of the PEG backbone. The rapid on-demand degradation of these hydrogels is also demonstrated by using cytocompatible light wavelength (λ = 365 nm) that degrades the photosensitive ONB units. The authors have successfully used these hydrogels as skin-worn sensors for monitoring human respiration and physical activities. A combination of excellent mechanical properties, facile fabrication, and on-demand degradation holds promise for their application as the next generation of substrates or active sensors eco-friendly for bioelectronics, biosensors, wearable computing, and stretchable electronics., (© 2023 Wiley-VCH GmbH.)- Published
- 2023
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13. Effect of Successive In-office Bleaching Sessions on the Surface Properties, Substance Loss, Biaxial Flexural Strength, and Reliability of CAD-CAM Monolithic Materials.
- Author
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Queiroz J, Fernandes L, Dovigo LN, and Fonseca RG
- Subjects
- Reproducibility of Results, Materials Testing, Computer-Aided Design, Surface Properties, Dental Porcelain, Flexural Strength, Ceramics
- Abstract
Little is known about the effects of in-office bleaching on the surface properties and on other aspects of CAD-CAM monolithic materials, especially when successive bleaching sessions are conducted. This study evaluated the effect of up to three successive in-office bleaching sessions on the microhardness, roughness, topography, substance loss, biaxial flexural strength (BFS), and reliability of CAD-CAM monolithic materials. Disks from Lava Ultimate (LU), Vita Enamic (VE), and IPS Empress CAD (EMP) were fabricated and submitted to one, two, and three bleaching sessions. In-office bleaching was performed with 40% hydrogen peroxide and each session consisted of three applications of 20 minutes each. The analyses regarding the aforementioned parameters were assessed before and after the first, second, and third bleaching sessions, except for BFS, which was evaluated at the baseline and after the third session. Weibull modulus was calculated from the BFS data. Bleaching decreased the microhardness of LU and VE from the third and second sessions, respectively, and affected neither the roughness nor the BFS of the three materials. However, in LU, it decreased the reliability and caused topographic changes, which were accentuated by the increase in the number of sessions. In general, LU and EMP showed, respectively, the highest and the lowest substance losses. Successive in-office bleaching sessions with the use of the protocol of the present study should be avoided in LU and VE., (© Operative Dentistry, 2023.)
- Published
- 2023
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14. Photo-degradable, tough and highly stretchable hydrogels.
- Author
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Fonseca RG, De Bon F, Pereira P, Carvalho FM, Freitas M, Tavakoli M, Serra AC, Fonseca AC, and Coelho JFJ
- Abstract
We present for the first time highly stretchable and tough hydrogels with controlled light-triggered photodegradation. A double-network of alginate/polyacrylamide (PAAm) is formed by using covalently and ionically crosslinked subnetworks. The ionic Ca
2+ alginate interpenetrates a PAAm network covalently crosslinked by a bifunctional acrylic crosslinker containing the photodegradable o -nitrobenzyl (ONB) core instead of the commonly used methylene bisacrylamide (MBAA). Remarkably, due to the developed protocol, the change of the crosslinker did not affect the hydrogel's mechanical properties. The incorporation of photosensitive components in hydrogels allows external temporal control of their properties and tuneable degradation. Cell viability and cell proliferation assays revealed that hydrogels and their photodegradation products are not cytotoxic to the NIH3T3 cell line. In one example of application, we used these hydrogels for bio-potential acquisition in wearable electrocardiography. Surprisingly, these hydrogels showed a lower skin-electrode impedance, compared to the common medical grade Ag/AgCl electrodes. This work lays the foundation for the next generation of tough and highly stretchable hydrogels that are environmentally friendly and can find applications in a variety of fields such as health, electronics, and energy, as they combine excellent mechanical properties with controlled degradation., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors. Published by Elsevier Ltd.)- Published
- 2022
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15. Long-term effects of simulated gastric juice alternated with brushing on hardness, substance loss, flexural strength and reliability of CAD-CAM monolithic materials.
- Author
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Oliveira Junior JR, Cruz MEMD, Dovigo LN, and Fonseca RG
- Subjects
- Ceramics chemistry, Computer-Aided Design, Gastric Juice, Hardness, Humans, Materials Testing, Reproducibility of Results, Saliva, Artificial, Surface Properties, Dental Porcelain chemistry, Flexural Strength
- Abstract
Objectives: The purpose of this study is to evaluate, over a simulated 5-year period, the effect of simulated gastric juice alternated with brushing on CAD-CAM monolithic materials considering microhardness, substance loss, flexural strength, and reliability of the materials., Methodology: Blocks from Lava Ultimate (LU), Vita Enamic (VE), IPS Empress CAD (EMP), IPS e.max CAD (EMAX), and Vita Suprinity (VS) were milled into cylinders and sliced into disks. The EMAX and VS were crystallized, and all specimens were polished with silicon carbide papers and allocated as follows: 1) artificial saliva + brushing or 2) simulated gastric juice (0.113% hydrochloric acid (HCl) solution in deionized water, pH 1.2) + brushing, simulating 1, 3, and 5 years of clinical function. Each year of clinical function was simulated by three repetitions of immersion for 3 hours in artificial saliva or simulated gastric juice followed by 1,217 brushing cycles. The microhardness and substance loss were evaluated at baseline (T0) and at each year by using a Vickers hardness tester and an analytical balance. The biaxial flexural strength (BFS) test was performed in a mechanical testing machine at the end of the 5th year. Weibull modulus was calculated from the BFS data., Results: The microhardness of the LU was not influenced by the treatment, whereas that of the other materials, in certain years, was significantly lower in the gastric juice + brushing groups in comparison with artificial saliva + brushing groups. In general, the materials did not present a significant change in microhardness over time, for either of the treatments. The LU alone showed greater substance loss in the gastric juice + brushing groups for every year. In both treatments, the LU, VE, and EMP exhibited a significant increase in the substance loss over time. The treatment did not affect the BFS of the materials. The gastric juice + brushing decreased the reliability of the VE., Conclusions: All materials were somehow impaired by the gastric juice + brushing in at least one of the evaluated parameters, except for the BFS. However, in a deeper analysis, the LU would be the least indicated materials, followed by VE, for patients with eating disorders.
- Published
- 2022
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16. Long-term effect of gastric juice alternating with brushing on the surface roughness, topography, and staining susceptibility of CAD-CAM monolithic materials.
- Author
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da Cruz MEM, Oliveira JJR, Dovigo LN, and Fonseca RG
- Subjects
- Ceramics, Color, Computer-Aided Design, Gastric Juice, Humans, Materials Testing, Saliva, Artificial, Staining and Labeling, Surface Properties, Coffee, Dental Porcelain
- Abstract
Statement of Problem: Studies on the behavior of computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic materials subjected to gastric juice alternating with brushing-as occurs in patients with bulimia nervosa-are lacking., Purpose: The purpose of this in vitro study was to evaluate, over a simulated 5-year period, the effect of gastric juice alternating with brushing on the roughness, topography, and staining susceptibility of CAD-CAM monolithic materials., Material and Methods: Disks of Lava Ultimate (LU), Vita Enamic (VE), IPS Empress CAD (EMP), IPS e.max CAD (EMAX), and Vita Suprinity (VS) were randomly allocated to artificial saliva+brushing or gastric juice+brushing groups, simulating 1, 3, and 5 years of clinical function. The roughness (Sa) and topography were evaluated at baseline (T
0 ) and at each simulated year. For the staining susceptibility (ΔE00 ), the CIELab color coordinates were registered at baseline, and, at the end of the fifth simulated year, the specimens were immersed in deionized water, coffee, or cola before the second reading. Roughness data were submitted to mixed repeated-measures ANOVA and Bonferroni, and the staining susceptibility data were analyzed by 3-way ANOVA and the Games-Howell test (α=.05)., Results: The gastric juice+brushing led to higher roughness than artificial saliva+brushing only in the VE at T3 and T5 (P<.01). In both treatments, the LU and VE showed topography changes and an increase in roughness over time (P<.001), in addition to higher roughness than the other materials (P<.001). The staining susceptibility of the materials to each staining solution was not affected by the treatment (P>.05). The LU and VS groups were more stained by coffee (P<.001), while the VE and EMP groups were more stained by cola (P≤.016), except for the EMP in the gastric juice+brushing, where no significant difference was found between cola and coffee (P>.05). The EMAX was imperceptibly affected by the 3 solutions., Conclusions: Concerning roughness and topography, the LU and VE were the most affected by both treatments. The staining susceptibility of the materials was not affected by the treatment., (Copyright © 2022 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)- Published
- 2022
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17. Analgesic efficacy of a portable, disposable, and self-applied transcutaneous electrical nerve stimulation device during migraine attacks: A real-life randomized controlled trial.
- Author
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Domingues FS, Gayoso MV, Sikandar S, da Silva LM, Fonseca RG, and de Barros GAM
- Subjects
- Adult, Analgesics, Double-Blind Method, Humans, Pain Measurement, Treatment Outcome, Migraine Disorders therapy, Transcutaneous Electric Nerve Stimulation
- Abstract
Objective: The objective of this study was to evaluate the analgesic efficacy of a portable, disposable, and home self-applied transcutaneous electrical nerve stimulation (TENS) device during migraine attacks., Background: TENS has been used as a noninvasive treatment for migraine, but there are no reports on the outcomes following use of this treatment option for use at home during migraine attacks., Design and Methods: A double-blind, randomized controlled trial was conducted over 3 months, with monthly assessments. Active placebos (sham group) were in place and were allocated at a 1:1 ratio. Adult patients who had been diagnosed with migraine by a specialist were included. Pain intensity levels and functional disability were measured before and after the 20-min self-applied TENS intervention during the migraine attacks., Results: Seventy-four participants were randomly allocated to the sham and intervention groups. Although both groups of subjects reported lower pain scores, the intervention group showed a statistically significant reduction in pain scores compared to the sham group., Conclusion: In our controlled trial, the use of a self-applied, TENS device is safe and effective in relieving pain associated with migraine attacks. Participants in the intervention group showed a statistically significant improvement in pain and functional disability scores. TENS has been used as a noninvasive treatment for migraine, but there are no reports on the outcomes following use of this treatment option for use at home during migraine attacks. This double-blind, randomized controlled trial had 2 groups: active-placebo and intervention. Seventy-four participants were randomly allocated. Participants in the intervention group showed a statistically significant improvement in pain and functional disability scores., (© 2021 World Institute of Pain.)
- Published
- 2021
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18. Effect of In-office Bleaching on Color, Translucency, and Whiteness Variations in CAD-CAM Monolithic Materials.
- Author
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Peña RC, Simóes R, Ramos AC, Dovigo LN, and Fonseca RG
- Subjects
- Color, Computer-Aided Design, Dental Porcelain, Materials Testing, Surface Properties, Ceramics, Composite Resins
- Abstract
Little is known about the impact of bleaching on the optical properties of computer-aided design and computer-aided manufactured (CAD-CAM) monolithic materials. The aim of the present study was to evaluate the effect of one session of in-office bleaching on stain removal, staining susceptibility, translucency, and whiteness variations of CAD-CAM monolithic materials. Disks were fabricated from Lava Ultimate (LU), Vita Enamic (VE), Vita Suprinity (VS), and IPS e.max CAD (IPS). A spectrophotometer was used to register Commission Internationale de l'Eclairage L*a*b* coordinates. For stain removal, 80 specimens from each material were assessed at baseline (R0) and after immersion in deionized water or coffee for 36.5 days followed or not by bleaching with 40% hydrogen peroxide (R1). For staining susceptibility, 80 specimens from each material were analyzed at baseline (R0'), and after having been bleached or not and immersed in deionized water or coffee (R1'). Both analyses were calculated as the color difference (ΔE00) between R1-R0 and R1'-R0', respectively. Differences in translucency (ΔTP00) and whiteness (ΔWID) between R1-R0 and R1'-R0' were also calculated. Data were analyzed by three-way ANOVA and the Games-Howell post hoc test (α=0.05). Clinical significance was based on 50%:50% perceptibility and acceptability thresholds for ΔE00, ΔTP00 and ΔWID, respectively. Surfaces were analyzed by scanning electron microscopy. Coffee increased ΔE00 in LU, VE, and VS, and decreased their translucency and whiteness, whereas the IPS had only its whiteness affected. Bleaching after immersion in coffee decreased ΔE00 in LU and VE, and increased translucency and whiteness of LU, VE, and VS. No effect was observed on IPS. Bleaching before immersion in coffee decreased translucency of LU, but within the acceptable interval, while VE exhibited lower ΔE00, and became more translucent and less dark. Both VS and IPS were not affected. One session of in-office bleaching benefited optical properties of the previously stained LU, VE, and VS, without increasing their susceptibility to staining or adversely providing clinically unacceptable variations in their translucency and whiteness. All variations exhibited by the IPS were below the perceptible threshold., (© Operative Dentistry, 2021.)
- Published
- 2021
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19. [Bodily practices in imperial legislation and constructing a professional sociology for physical education].
- Author
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Fonseca RG, Honorato T, and Souza Neto S
- Abstract
This documentary study examines official texts related to physical education in legislation and decrees from Brazil's imperial period (1822-1889) to trace the initial steps of professionals in this area within the civil and military context of Brazilian society, before they were recognized as a professional category. We found that unlike intellectual efforts, practical work was less attractive, which made it difficult for these professionals to work exclusively and maintain stability in this area. These elements were obstacles to more organized demands from physical education that were required for professionalization.
- Published
- 2021
- Full Text
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20. Influence of simulated gastric juice on surface characteristics of CAD-CAM monolithic materials.
- Author
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Cruz MEM, Simões R, Martins SB, Trindade FZ, Dovigo LN, and Fonseca RG
- Subjects
- Ceramics, Computer-Aided Design, Dental Materials, Gastric Juice, Materials Testing, Surface Properties, Dental Porcelain, Esthetics, Dental
- Abstract
Statement of Problem: How the surfaces of monolithic esthetic restorations behave in the presence of acidic substances is unclear., Purpose: The purpose of this in vitro study was to evaluate the effect of simulated gastric juice on roughness, morphology, microhardness, substance loss, and color change of computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic materials., Material and Methods: Disks from Lava Ultimate, VITA ENAMIC, IPS e.max CAD, and VITA SUPRINITY were analyzed for roughness, morphology, and microhardness by using a confocal microscope, scanning electron microscope (SEM), and Vickers hardness tester. Substance loss was determined by weighing the specimens on an analytical balance, and color change (ΔE) was assessed by using a spectrophotometer based on the CIELab parameters. All analyses were carried out before and after acid exposure., Results: Acid exposure significantly decreased the roughness, having a very high effect size on this property. The material was highly decisive in determining the microhardness, presenting the following order: VITA SUPRINITY>IPS e.max CAD>VITA ENAMIC>Lava Ultimate. The mass was not significantly affected by the acidic challenge. No significant difference in ΔE was found between Lava Ultimate and VITA ENAMIC and between IPS e.max CAD and VITA SUPRINITY. Lava Ultimate showed a higher ΔE than IPS e.max CAD and VITA SUPRINITY, whereas VITA ENAMIC exhibited higher ΔE only when compared with VITA SUPRINITY. All materials presented ΔE<1., Conclusions: The simulated gastric juice significantly influenced the roughness of all the evaluated materials and promoted a color change classified as clinically undetectable in all materials., (Copyright © 2019 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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21. Analysis of patients with obstructive sleep apnea with and without pharyngeal myopathy using brain neuroimaging.
- Author
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Baima CB, Fim NC, Alves KF, Resende LAL, Fonseca RG, and Betting LE
- Subjects
- Brain diagnostic imaging, Humans, Magnetic Resonance Imaging, Neuroimaging, Pharynx, Muscular Diseases, Sleep Apnea, Obstructive complications, Sleep Apnea, Obstructive diagnostic imaging
- Abstract
Study Objectives: Elements impairing upper airway anatomy or muscle function (e.g. pharyngeal neuromyopathy) contribute to obstructive sleep apnea syndrome (OSAS). Structural brain imaging may differ in patients with OSAS according to dilator muscle dysfunction. Magnetic resonance imaging (MRI) with voxel-based morphometry (VBM) and surface-based morphometry (SBM) was used to investigate this hypothesis., Methods: Eighteen patients with OSAS and 32 controls underwent 3T brain MRI. T1 volumetric images were used for structural analysis. Pharyngeal electroneuromyography was performed; patients with OSAS were classified as with or without neuromyopathy. VBM and SBM analyses were conducted using SPM12 and CAT12 software. Image processing was standard. Cortical surface parameters and gray and white matter volumes from participants with OSAS with and without neuromyopathy were compared with those from controls., Results: Eleven patients had OSAS with neuromyopathy and seven patients had OSAS without neuromyopathy (normal pharyngeal electroneuromyography). Comparing these groups to the controls, VBM revealed: four clusters (total volume 15,368 mm3) for patients with neuromyopathy, the largest cluster in the left cerebellum (9,263 mm3, p = 0.0001), and three clusters (total 8,971 mm3) for patients without neuromyopathy, the largest cluster in the left cerebellum (5,017 mm3, p = 0.002). Patients with OSAS with neuromyopathy showed increased proportion of atrophy (p < 0.0001). SBM showed abnormalities in patients without neuromyopathy (decreased cortical thickness, left precentral gyrus [672 vertices, p = 0.04]; increased cortical complexity, right middle temporal gyrus [578 vertices, p = 0.032])., Conclusion: Damaged areas were larger in patients with OSAS with than in those without neuromyopathy, suggesting differences in brain involvement. Patients with OSAS and neuromyopathy may be more susceptible to cerebral damage., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)
- Published
- 2020
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22. Does airborne-particle abrasion before, rather than after, zirconia sintering lead to higher mechanical strength even under aging challenge?
- Author
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Martins SB, Trindade FZ, Góes MS, Adabo GL, Dovigo LN, and Fonseca RG
- Subjects
- Ceramics, Dental Stress Analysis, Materials Testing, Reproducibility of Results, Stress, Mechanical, Surface Properties, Yttrium, Dental Materials, Zirconium
- Abstract
Statement of Problem: Information concerning the effect of airborne-particle abrasion before zirconia sintering on its strength after aging is lacking., Purpose: The purpose of this in vitro study was to determine the influence of airborne-particle abrasion moment (before or after zirconia sintering), particle size, and aging on the mechanical strength of a yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic., Material and Methods: Four hundred presintered zirconia disks were allocated to nonabraded (control) and abraded groups with 50 μm or 120 μm Al
2 O3 particles before (50/BS or 120/BS) or after sintering (50/AS or 120/AS). The disks were aged by storing them in distilled water for 24 hours at 37 °C (24 h) (control); mechanical cycling (MC) (1×106 cycles; 2 Hz; 100 N); hydrothermal aging (HA) (134 °C; 0.2 MPa; 20 hours); or by both methods (MC+HA), totaling 20 groups (n=20). The specimens were subjected to biaxial flexural strength (BFS) testing. Fractographic analysis was performed to identify the fracture origin. Tetragonal to monoclinic transformation was determined by X-ray diffraction. The BFS data (MPa) were analyzed by 2-way ANOVA and the Games-Howell post hoc test (α=.05). Weibull statistics was also applied., Results: The BFS and characteristic strength (σ0) of the 120/AS groups were significantly higher compared with the other abraded groups and statistically similar or higher compared with the respective nonabraded groups. In contrast, the 120/BS/24 h and all the 50/BS groups presented the lowest values. In all groups, the initial defect had its origin on the tensile stress side. Neither airborne-particle abrasion nor aging (except for the 50/AS/MC+HA) reduced the zirconia reliability compared with the respective controls. Abrading the zirconia in its presintered stage or after sintering increased the monoclinic phase content, and the sintering process eliminated this phase., Conclusions: Airborne-particle abrasion before zirconia sintering yields an inferior performance compared with that after sintering under aging challenges. The BFS and σ0 were strongly determined by the particle size and airborne-particle abrasion moment, while aging mainly acted in the nonabraded zirconia or when this material was abraded before sintering., (Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)- Published
- 2020
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23. Fatigue resistance of monolithic lithium disilicate occlusal veneers: a pilot study.
- Author
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Baldissara P, Monaco C, Onofri E, Fonseca RG, and Ciocca L
- Subjects
- Ceramics, Dental Stress Analysis, Humans, Materials Testing, Pilot Projects, Dental Porcelain, Dental Restoration Failure
- Abstract
The use of thin lithium disilicate (LD) occlusal veneers is an effective method to increase the vertical dimension of occlusion in cases of tooth wear. However, doubt remains regarding the threshold thickness to be used in this restoration class. This study aims to evaluate the effect of ceramic thickness on the survival rate and failure pattern of LD molar veneer restorations using a simplified fatigue testing machine. Sixty sound, freshly extracted human molars were used. Three groups (n = 20) were randomly created with different ceramic thicknesses (0.5, 0.8, and 1.2 mm), and 60 LD IPS e.max Press LT occlusal veneers were fabricated. The ceramic restorations were luted with a resin cement. The stainless-steel rotating drum of the ball mill contained 10 zirconia (Y-TZP) and 10 stainless steel spheres, in 500 mL of distilled water at 37 ± 1 °C. Crack growth in the LD restorations was evaluated under a stereomicroscope following each fatigue testing run (12 60-min runs). Progressive damage was observed as a function of cycling time. Survival was significantly influenced by the restoration thickness (p = 0.002, log-rank test), with thicker restorations exhibiting a higher survival rate. Thinner restorations (0.5 mm) showed significantly lower survival rate than 0.8- and 1.2-mm restorations (p < 0.016); no significant difference was observed between the 0.8- and 1.2-mm restorations. A threshold value of 0.8 mm may represent an acceptable compromise between fatigue resistance and tooth reduction.
- Published
- 2019
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24. Effect of grinding and polishing on the roughness and fracture resistance of cemented CAD-CAM monolithic materials submitted to mechanical aging.
- Author
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Ludovichetti FS, Trindade FZ, Adabo GL, Pezzato L, and Fonseca RG
- Subjects
- Computer-Aided Design, Materials Testing, Reproducibility of Results, Surface Properties, Ceramics, Dental Porcelain
- Abstract
Statement of Problem: The effect of clinical adjustments on the strength of cemented computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic materials under aging challenge is unclear., Purpose: The purpose of this in vitro study was to assess the surface roughness and fracture resistance (with or without mechanical aging) of cemented CAD-CAM monolithic materials submitted to grinding and polishing procedures., Material and Methods: Disks of Lava Ultimate, Vita Enamic, crystallized Vita Suprinity, and IPS e.max CAD were analyzed for roughness after polishing by using silicon carbide papers (Lava Ultimate and Vita Enamic) or glazing (IPS e.max CAD and Vita Suprinity) (control), after grinding by using 30-μm grit diamond rotary instruments, and after grinding and polishing by using a polishing kit. For fracture resistance, a simplified trilayer model consisting of a restorative disk, an epoxy resin disk, and a steel ring was used. The bonded trilayer disks received the same treatments described for the roughness analysis. Half of the specimens underwent mechanical aging for 1×10
6 cycles. All specimens were loaded until failure. The Weibull modulus was calculated., Results: The IPS e.max CAD and Vita Suprinity showed the highest roughness after grinding and the lowest at baseline. For the Lava Ultimate and Vita Enamic, polishing provided lower roughness than at baseline. Grinding, followed or not by polishing, and mechanical aging did not adversely affect the fracture resistance or the reliability of the materials., Conclusions: Polishing did not recover the initial surface roughness of the glass-ceramic materials. Fracture resistance was not affected by grinding, followed or not by polishing, even after mechanical aging., (Copyright © 2019 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)- Published
- 2019
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25. Influence of Particle and Air-Abrasion Moment on Y-TZP Surface Characterization and Bond Strength.
- Author
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Martins SB, Abi-Rached FO, Adabo GL, Baldissara P, and Fonseca RG
- Subjects
- Aluminum Oxide chemistry, Analysis of Variance, Bisphenol A-Glycidyl Methacrylate, Composite Resins chemistry, Dental Bonding, Dental Cements, Dental Materials chemistry, Dental Restoration Failure, Dental Stress Analysis, Humans, Materials Testing, Microscopy, Electron, Scanning, Particle Size, Polyethylene Glycols, Polymethacrylic Acids, Silicon Dioxide chemistry, Surface Properties, Wettability, Air Abrasion, Dental methods, Resin Cements chemistry, Shear Strength, Yttrium chemistry, Zirconium chemistry
- Abstract
Purpose: To evaluate the influence of particle and air-abrasion on the surface characterization and shear bond strength (SBS) of a Y-TZP ceramic with a resin cement., Materials and Methods: Y-TZP specimens were air-abraded with 50 μm alumina particles; 120 μm alumina particles; 30 μm silica-coated alumina particles (Rocatec Soft); 110 μm silica-coated alumina particles (Rocatec Plus). Air-abrasion was performed before (BS); after (AS); before and after (BAS) zirconia sintering. Surface characterization included roughness (n = 10), wettability (n = 10), morphology (n = 2), and elemental composition (n = 2). For SBS (n = 11), composite resin discs were bonded to the air-abraded and silane-treated zirconia surface, with the resin cement RelyX ARC. Failure mode was determined. Roughness, wettability, and SBS data were analyzed by two-way ANOVA with pairwise interaction and Tukey's test (α = 0.05)., Results: Air-abrasion performed with coarser particles at BS and BAS moments provided the highest roughness values, while the lowest roughness values were observed with particles combined with AS moment (p < 0.01). Rocatec Plus provided lower contact angle than the 120 μm alumina particles (p = 0.013), and BAS exhibited lower contact angle than BS (p = 0.002). The combinations 120 μm/BS and the silica-coated alumina particles/AS and /BAS showed the highest SBS (p < 0.05). The combination of each particle/BAS was statistically similar to the same particle/AS. Failure mode was 100% adhesive for all groups. The interaction particle size/air-abrasion moment determined the morphological pattern. Silicon was observed only in the Rocatec groups., Conclusions: Roughness was influenced by the particle size and was higher when the zirconia was air-abraded in its green stage. The particle composition played an important role in the wettability and both studied air-abrasion moments provided similar wettability than the one in which air-abrasion is usually performed. The highest SBS values were observed in the three moments, by using certain particles for each moment., (© 2017 by the American College of Prosthodontists.)
- Published
- 2019
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26. Marginal Fit of Metal-Ceramic Copings: Effect of Luting Cements and Tooth Preparation Design.
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de Almeida JGDSP, Guedes CG, Abi-Rached FO, Trindade FZ, and Fonseca RG
- Subjects
- Dental Alloys chemistry, Dental Porcelain chemistry, Dental Prosthesis Design, Dental Restoration Failure, Glass Ionomer Cements chemistry, Humans, Resin Cements, Stress, Mechanical, Surface Properties, Tooth Preparation methods, Cementation methods, Dental Cements chemistry, Dental Marginal Adaptation, Materials Testing, Metal Ceramic Alloys chemistry, Tooth Preparation, Prosthodontic methods
- Abstract
Purpose: To evaluate the effect of the triad finish line design, axial wall convergence angle, and luting cement on the marginal fit of metal copings used in metal-ceramic crowns., Materials and Methods: Schematic dies and their respective copings were cast in NiCr alloy. The dies exhibited the following finish line/convergence angle combinations: sloping shoulder/6°, sloping shoulder/20°, shoulder/6°, shoulder/20°. Marginal fit was evaluated under a stereomicroscope, before and after cementation. Copings were air-abraded with 50 μm Al
2 O3 particles and cemented with Cimento de Zinco, RelyX U100, or Panavia F cements (n = 10/group). Data were square-root transformed and analyzed by 3-way factorial random effect model and Tukey's post hoc test (α = 0.05)., Results: Statistical analysis showed significance for the interactions finish line and convergence angle (p < 0.05), convergence angle and time (p < 0.001), and luting cement and time (p < 0.001). Sloping shoulder/20° provided the highest marginal discrepancy when compared to the other finish line/convergence angle combinations, which were statistically similar among each other. For both convergence angles and for all luting cements, the marginal discrepancy was significantly higher after cementation. Before and after cementation, 6° provided better marginal fit than 20°. After cementation, Panavia F provided higher marginal discrepancy than Cimento de Zinco., Conclusion: Lower convergence angle combined with shoulder and a low-consistency luting cement is preferable to cement metal copings., (© 2017 by the American College of Prosthodontists.)- Published
- 2019
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27. Effect of the Auricular Acupoint Associated with Physical Exercise in Elderly People: A Randomized Clinical Test.
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de Carvalho Fonseca RG, Silva AM, Teixeira LF, Silva VR, Dos Reis LM, and Silva Santos AT
- Subjects
- Accidental Falls, Aged, Aged, 80 and over, Aging psychology, Exercise, Fear, Female, Humans, Male, Postural Balance, Acupuncture Points, Acupuncture, Ear, Aging physiology
- Abstract
Objective: To analyze the effect of auricular acupoint associated with physical exercise on balance, mobility, and fear of falling in the elderly., Method: The study is characterized as a clinical, controlled, and randomized trial with 22 elderly people divided into two groups: kinesiotherapy group (n = 11) and kinesiotherapy/auriculotherapy group (n = 11). The instruments used for evaluation were Falls Efficacy Scale International; Berg Balance Scale, and Timed up and Go Test. The intervention was performed with frequency 2×/week for 8 weeks. In the kinesiotherapy/auriculotherapy group, in addition to kinesiotherapy, auriculotherapy was applied in specific acupoints. The Shapiro-Wilk test was used to determine the normality of the data, and for comparison, analysis of variance was used for repeated measures of two factors., Results: There was a significant intragroup reduction for the Timed up and Go Test (p = 0.00) and Falls Efficacy Scale International (p = 0.00), and significant intragroup Berg Balance Scale (p = 0.00) for both groups., Conclusion: The auricular acupoint did not influence the balance, mobility, and fear of falling in the elderly studied., (Copyright © 2018. Published by Elsevier B.V.)
- Published
- 2018
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28. Wear resistance and abrasiveness of CAD-CAM monolithic materials.
- Author
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Ludovichetti FS, Trindade FZ, Werner A, Kleverlaan CJ, and Fonseca RG
- Subjects
- Acrylic Resins, Animals, Cattle, Ceramics, Dental Prosthesis Design methods, Hardness, In Vitro Techniques, Polyurethanes, Surface Properties, Zirconium, Composite Resins chemistry, Computer-Aided Design, Dental Materials chemistry, Dental Porcelain chemistry, Materials Testing, Mechanical Phenomena
- Abstract
Statement of Problem: Computer-aided design and computer-aided manufacturing (CAD-CAM) restorations are in contact with the antagonist tooth, either a natural tooth or a restoration. Therefore, clinicians should be aware of the wear resistance of CAD-CAM materials and the wear behavior of the antagonist., Purpose: The purpose of this in vitro study was to evaluate the wear resistance and abrasiveness of CAD-CAM materials., Material and Methods: In a 2-body wear test, the materials IPS e.max CAD (Ivoclar Vivadent AG), Vita Suprinity (Vita Zahnfabrik), Lava Ultimate (3M ESPE), Vita Enamic (Vita Zahnfabrik), and Lava Plus (3M ESPE) acted as abraders and, together with bovine enamel, also as antagonists. Each antagonist wheel ran against each abrader wheel for 200000 cycles, with a spring force of 15 N, and at a rotational speed of 1 Hz in distilled water. The wear rate was determined with a surface profilometer. The surfaces were observed with scanning electron microscopy, and their hardness, coefficient of friction, and roughness were evaluated., Results: Lava Plus and IPS e.max CAD exhibited the highest potential for wear of Lava Ultimate. These 2 materials, together with Vita Suprinity, provided the highest wear of enamel and Vita Enamic. Vita Suprinity and IPS e.max CAD had higher wear than Lava Plus, and the inverse was also true. Vita Enamic and Lava Ultimate were among the materials that caused the lowest wear of enamel and all other evaluated materials. Scanning electron microscopy images revealed that except for Lava Ultimate, all other materials damaged enamel, in which Vita Suprinity and IPS e.max CAD were more aggressive when sliding against the materials. Lava Plus had the greatest hardness, followed by Vita Suprinity and IPS e.max CAD, Vita Enamic, and then Lava Ultimate. The coefficient of friction varied from 0.42 to 0.53. The Vita Enamic and Lava Ultimate showed the highest surface roughness., Conclusions: The nanofilled composite resin and polymer-infiltrated ceramic were more antagonist-friendly (whether enamel or CAD-CAM material) than glass-ceramics and zirconia. Care should be taken when selecting the material that will contact mainly with glass-ceramics. Hardness should also be considered when selecting a material., (Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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29. Effect of surface treatments on repair with composite resin of a partially monoclinic phase transformed yttrium-stabilized tetragonal zirconia.
- Author
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Galvão Ribeiro BR, Galvão Rabelo Caldas MR, Almeida AA Jr, Fonseca RG, and Adabo GL
- Subjects
- Dental Bonding methods, Dental Etching methods, Dental Stress Analysis, Humans, In Vitro Techniques, Composite Resins therapeutic use, Dental Prosthesis Repair methods, Yttrium adverse effects, Yttrium therapeutic use, Zirconium adverse effects, Zirconium therapeutic use
- Abstract
Statement of Problem: Studies of composite resin repairs of yttrium-tetragonal zirconia polycrystal (Y-TZP) are usually performed in its tetragonal phase, but it may be partially transformed into a monoclinic phase in a clinical fracture., Purpose: The purpose of this in vitro study was to evaluate the effect of airborne-particle abrasion (APA) and a bonding agent on the shear bond strength (SBS) between a composite resin and hydrothermally aged Y-TZP., Material and Methods: Specimens (7.0×7.0×1.7 mm, N=112) of Y-TZP Lava were obtained, and 50% were aged in an autoclave at 134°C at 300 kPa for 8 hours. The surfaces were treated with APA 50-μm Al
2 O3 particles (ALU) or Rocatec Soft (30 μm) (ROC) followed by Clearfil SE Bond Primer (10-methacryloyloxydecyl dihydrogen phosphate [10-MDP]) plus Clearfil porcelain bond activator (3-methacryloxypropyl-trimethoxy silane [3-MPS]) (CLE) or RelyX Ceramic Primer plus a layer of RelyX U100 adhesive-resin cement (REL). Composite resin cylinders were built on the Y-TZP treated surfaces. After thermocycling (6000 cycles, 5°C and 55°C, 30-second dwell time), an SBS test was carried out (n=14). Data were analyzed by 3-way ANOVA and the Tukey honest significant differences test (α=.05). The failure mode was analyzed., Results: The 3-way ANOVA was not significant for aging (P>.05), but the APA (P<.001), bonding agent (P<.001), and their interaction (P<.001) were significant. APA with ALU or ROC did not influence the SBS of the groups bonded with CLE, but the REL APA with ROC provided higher SBS. The failure mode was adhesive for all specimens., Conclusions: Adhesion was not different on monoclinic partially transformed Y-TZP. The APA with ROC followed by REL was the most effective treatment for repairing Y-TZP., (Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)- Published
- 2018
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30. Effect of Glaze Cooling Rate on Mechanical Properties of Conventional and Pressed Porcelain on Zirconia.
- Author
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Longhini D, Rocha CO, Medeiros IS, Fonseca RG, and Adabo GL
- Subjects
- Temperature, Dental Porcelain chemistry, Materials Testing, Zirconium chemistry
- Abstract
The aim of this study was to characterize a conventional and a pressed porcelain for zirconia core as to biaxial flexural strength (BFS), apparent fracture toughness (FT) and microstructure composition, and to investigate the effect of glaze cooling rate on the BFS of the zirconia/porcelain bilayers. Monolayers of conventional porcelain Vita VM9 and pressed porcelain Vita PM9 (n=15) (12 mm diameter x 1.2 mm thick) were prepared for the BFS test (MPa). Apparent fracture toughness (MPa.m1/2) was measured by indentation technique (n=15). t-Student test was performed for statistical analysis. Scanning electron microscopy and x-ray diffraction were used to analyze the porcelain's microstructure. For the BFS of bilayers, zirconia discs (12 mm diameter x 1 mm thick) (Vita In-Ceram YZ) were veneered with the two porcelains (1 mm thick). After the glaze firing simulation, the specimens were submitted to fast or slow cooling (n=15). Apparent fracture toughness (MPa.m1/2) was measured on the porcelain surface of bilayers (n=15) and residual stress was calculated. Two-way ANOVA (porcelain and cooling method) was used for the bilayer analysis (a=0.05). Vita PM9 monolayer exhibited significantly higher BFS (p<0.01), but there was no significant difference (p=0.41) in the FT between the porcelains. For bilayer specimens, the two-way ANOVA for BFS was significant for the porcelain variable only (p<0.01) better for Vita PM9/zirconia. Two-way ANOVA for the FT for the bilayers was not significant for any variable. All groups showed compressive residual stresses. The pressed porcelain seems to be mechanically more effective for zirconia veneering.
- Published
- 2016
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31. Physicochemical and antimicrobial properties of copaiba oil: implications on product quality control.
- Author
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Fonseca RG, Barros FM, Apel MA, Poser GL, Andriolli JO, Filho PC, Sousa DF, Lobo IP, and Conceiç O AO
- Subjects
- Anti-Infective Agents pharmacology, Brazil, Chemical Phenomena, Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Dietary Supplements economics, Disk Diffusion Antimicrobial Tests, Gas Chromatography-Mass Spectrometry, Gram-Negative Bacteria drug effects, Gram-Negative Bacteria growth & development, Gram-Positive Bacteria drug effects, Gram-Positive Bacteria growth & development, Hydrogen-Ion Concentration, Plant Oils economics, Solubility, Spectrometry, Mass, Electrospray Ionization, Tandem Mass Spectrometry, Terpenes chemistry, Terpenes pharmacology, Volatile Organic Compounds chemistry, Volatile Organic Compounds pharmacology, Yeasts drug effects, Yeasts growth & development, Anti-Infective Agents chemistry, Dietary Supplements analysis, Fabaceae chemistry, Food Quality, Plant Oils chemistry, Terpenes analysis, Volatile Organic Compounds analysis
- Abstract
Background: The copaiba oil is a common natural product used in cosmetic industry and as a nutraceutical product. However, lack of quality control and scarce knowledge about its antimicrobial activity is a point of concern. The proposal of this study was to investigate the physicochemical properties and the antimicrobial activity of five commercial brands of copaiba oil., Methods: Acidity and ester index, refractory index, solubility in alcohol, and thin layer chromatography were performed to verify the physicochemical properties of five commercial copaiba oils sold in local pharmacies. Ultra performance liquid chromatography coupled with diode-array detection and electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-DAD/ESI-Q-TOF-MS) was used to investigate diterpene acids while the volatile compounds were analysed by gas chromatography-mass spectrometry (GC-MS). Antibacterial and antifungal activities were also evaluated by agar diffusion technique; and minimal inhibitory concentration and maximal bactericidal concentration were defined for each sample and bacteria., Results: The physical-chemical analysis revealed heterogeneity between all samples analysed. The A1 sample showed characteristics of copaiba oil and was mainly composed by hydrocarbon sesquiterpenes (29.95% β-bisabolene, 25.65% Z-α-bergamotene and 10.27% β-cariophyllene). Among diterpene acids, the UPLCDAD/ESI-Q-TOF-MS data are compatible with presence of copalic and/or kolavenic acid (m/z 305 [M + H]+). Candida albicans was sensitive to almost all samples at high concentration and Saccaromyces. Cerevisiae showed sensitivity to A1 sample at 100 mg/mL. Although variable, all samples showed antibacterial activity. Significant activity was seen for A3 (19.0 ±0 and 15.6 ±0.5 mm), A4 (16.6 ±0.5 and 15.6 ±0 mm), and A5 (17.1 ±0 and 17.1 ±0 mm) on Staphylococcus saprophyticus and S. aureus, respectively. All samples were active against Klebsiella pneumoniae showing ≥15 mm diameter halo inhibition; and only A2 was active against Eschirichia coli. Phytopatogens tested revealed resistance of Ralstonia solanacearum CGH12 to all samples and susceptibility of Xcv 112 strain of Xanthomonas campestris pv campestris to almost all samples. MIC and MMC showed bacteriostatic effect against clinical interest bacteria and bactericidal effect against phytopatogens., Conclusions: The results from physicochemical analysis reinforce the fact that it is imperative to include simple conventional methods in the analysis of oil products. The analysis of copaiba oil gives safe products and purity which ensure products with quality. Also, since copaiba oil is an over-the-counter product the results indicate that pharmacosurveillance must be improved by the governmental regulation agency to avoid microorganism resistance selection and to achieve better international quality products.
- Published
- 2015
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32. Effect of surface treatments on the shear bond strength of luting cements to Y-TZP ceramic.
- Author
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Sciasci P, Abi-Rached FO, Adabo GL, Baldissara P, and Fonseca RG
- Subjects
- Aluminum Oxide chemistry, Bisphenol A-Glycidyl Methacrylate chemistry, Coated Materials, Biocompatible chemistry, Composite Resins chemistry, Dental Stress Analysis instrumentation, Glass Ionomer Cements chemistry, Hot Temperature, Humans, Materials Testing, Microscopy, Electron, Scanning, Particle Size, Polyethylene Glycols chemistry, Polymethacrylic Acids chemistry, Shear Strength, Silanes chemistry, Silicon Dioxide chemistry, Spectrometry, X-Ray Emission, Stress, Mechanical, Surface Properties, Ceramics chemistry, Dental Bonding, Dental Etching methods, Dental Materials chemistry, Resin Cements chemistry, Yttrium chemistry, Zirconium chemistry
- Abstract
Statement of Problem: Because zirconia is a glass-free material, alternative surface treatments such as airborne-particle abrasion or silica coating should be used for long-term bonding. However, these surface treatments in combination with different bonding agents and luting cements have not yet been studied., Purpose: The purpose of the study was to evaluate the effect of surface treatments on the shear bond strength (SBS) of luting cements to Y-TZP ceramic., Material and Methods: Zirconia disks (N=240) were airborne-particle abraded with the following particles (n=48): 50 μm Al2O3; 120 μm Al2O3; 30 μm silica-coated Al2O3 (Rocatec Soft); 120 μm Al2O3+110 μm silica-coated Al2O3 (Rocatec Plus); and Rocatec Plus. After silanization of the zirconia surface, composite resin disks were bonded with (n=12) RelyX Luting 2; RelyX ARC; RelyX U100; and Panavia F. The bonded specimens were thermocycled (10 000 cycles) and tested for SBS. Failure mode was determined with a stereomicroscope (×20). The morphology and elemental composition of airborne-particle abraded surfaces were evaluated with scanning electron microscopy (×500) and energy-dispersive x-ray spectroscopy (×50)., Results: Surface treatments, cements, and their interaction were significant (P<.001). For RelyX ARC, Rocatec Soft and Rocatec Plus provided the highest SBS. In general, surface treatments did not influence the SBS of RelyX U100 and Panavia F. Regardless of the cement, no significant difference was found between 50 μm and 120 μm Al2O3 particles, between Rocatec Soft and Rocatec Plus, or between Rocatec Plus and 120 μm Al2O3 particles+Rocatec Plus. All groups showed adhesive failures. Different particle sizes provided differences in morphological patterns. The elemental composition comprised Al and Al/Si for alumina and silica-abraded zirconia., Conclusions: Particle size did not influence the SBS of the groups abraded exclusively with alumina or silica-coated particles. RelyX ARC was more surface-treatment dependent than RelyX U100 or Panavia F., (Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
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33. Quantitative evaluation of taste in childhood populations: a systematic review.
- Author
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Moura RG, Cunha DA, Caldas AS, and Silva HJ
- Subjects
- Child, Evaluation Studies as Topic, Humans, Reproducibility of Results, Taste physiology
- Abstract
Introduction: Taste is of great importance for the feeding process. Seen in this light, it is essential to investigate this sense in children as developing human beings. However, despite little variation in the use of tests that measure the gustatory capacity, there are still questions about the applicability and effective use of tools for quantitative assessment in children., Objective: To search the literature on quantitative instruments used for the evaluation of taste used in studies with children., Methods: A search was conducted in the PUBMED and Web of Science platforms, and subsequently, the identified articles were selected and reviewed. The descriptors and terms used were "taste," "child," "assessment," "diagnosis," and "dysgeusia". Original articles related to the theme in English, restricted to children and with no year limitation, were selected. Studies conducted in other stages of human development, exclusively or concurrently with the pediatric population; animal studies; literature review articles; dissertations and book chapters; and case studies and editorials were excluded. The data analysis was performed through a cataloging protocol created for this study, including the following points: author, research department, year, location, population/sample, age, purpose of the study, methods, and primary results., Results: 5613 items were found. 5307 were excluded based on title, 248 by abstract analysis, and 43 by full text evaluation. Fifteen articles were selected for analysis; of these, six were repeated articles, and thus nine articles were selected for review., Conclusion: The tests aiming at evaluation of taste were judiciously used, ensuring reliability for future research, which may employ methods similar to previous studies., (Copyright © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.)
- Published
- 2015
- Full Text
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34. Evaluation of roughness, wettability, and morphology of an yttria-stabilized tetragonal zirconia polycrystal ceramic after different airborne-particle abrasion protocols.
- Author
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Abi-Rached FO, Martins SB, Campos JA, and Fonseca RG
- Subjects
- Aluminum Oxide chemistry, Coated Materials, Biocompatible chemistry, Hot Temperature, Humans, Materials Testing, Methacrylates chemistry, Microscopy, Electron, Scanning, Particle Size, Silanes chemistry, Silicon Dioxide chemistry, Surface Properties, Time Factors, Wettability, Ceramics chemistry, Dental Etching methods, Dental Materials chemistry, Yttrium chemistry, Zirconium chemistry
- Abstract
Statement of Problem: Airborne-particle abrasion is an effective method of roughening a zirconia surface and promoting micromechanical interlocks with luting cements. However, the effect of different airborne-particle abrasion protocols on the micromechanical retention mechanism has been poorly investigated., Purpose: The purpose of the study was to evaluate the effect of airborne-particle abrasion protocols on the surface roughness, wettability, and morphology of an yttria-stabilized tetragonal zirconia polycrystal ceramic., Material and Methods: A total of 140 zirconia specimens (14 × 14 × 1.4 mm) were made from Lava and divided into 7 groups. Their surfaces were treated as follows (n = 20): as-sintered (control); airborne-particle abraded with 50-μm Al2O3 particles; 120-μm Al2O3 particles; 250-μm Al2O3 particles; 30-μm silica-coated Al2O3 particles (Rocatec Soft); 110-μm silica-coated Al2O3 particles (Rocatec Plus); and 120-μm Al2O3 particles followed by Rocatec Plus. The surface roughness (Ra) and wettability analyses were performed on the same specimens of each group. The test liquid used for the wettability analysis was the silane RelyX Ceramic Primer. Two additional specimens (6.0 × 6.0 × 1.0 mm) per group were prepared to evaluate the surface morphology with scanning electron microscopy. The roughness (Ra) data were analyzed by 1-way ANOVA and the Dunnett C test (α = .05), and the wettability data with 1-way ANOVA (α = .05). The Spearman correlation analysis was applied to test for a possible correlation between roughness and wettability., Results: The control group (0.35 μm) exhibited the lowest mean roughness value (Ra), which was followed by Rocatec Soft (0.40 μm), 50-μm Al2O3 particles (0.52 μm), Rocatec Plus (0.69 μm), 120-μm Al2O3 particles (0.80 μm)/120-μm Al2O3 particles + Rocatec Plus (0.79 μm), and 250-μm Al2O3 particles (1.13 μm). No significant difference was found among the groups concerning wettability. No correlation (rs = -0.09; P = .27) was found between the 2 dependent variables. The scanning electron microscopy analysis indicated that the different airborne-particle abrasion protocols produced differences in the morphologic patterns., Conclusions: Although roughness and morphology of the zirconia surface varied according to the airborne-particle abrasion protocol, no close relationship was found between them. The roughness increase seemed to have followed the size of the particles., (Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)
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- 2014
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35. Effect of surface and heat treatments on the biaxial flexural strength and phase transformation of a Y-TZP ceramic.
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Fonseca RG, Abi-Rached Fde O, da Silva FS, Henriques BA, and Pinelli LA
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- Aluminum Oxide chemistry, Crystallography, Dental Etching methods, Dental Stress Analysis instrumentation, Dental Veneers, Diamond chemistry, Elastic Modulus, Hot Temperature, Materials Testing, Pliability, Silicon Dioxide chemistry, Stress, Mechanical, Surface Properties, Water chemistry, X-Ray Diffraction methods, Dental Porcelain chemistry, Yttrium chemistry, Zirconium chemistry
- Abstract
Purpose: To evaluate the effect of grinding and airborne-particle abrasion on the biaxial flexural strength (BFS) and phase transformation of a Y-TZP ceramic, and examine whether sintering the veneering porcelain renders the previous heat treatment recommended by the manufacturer unnecessary., Materials and Methods: Lava zirconia specimens (N = 108) were obtained with the following dimensions: 14.0 mm diameter × 1.3 mm thickness (n = 36) and 14.0 mm × 1.6 mm (n = 72). The thicker specimens were ground with diamond burs under irrigation and received (heat-treated groups) or not (non-heat-treated groups) a heat treatment (1000°C for 30 min) prior to the four firing cycles applied to simulate the sintering of the veneering porcelain. All specimens were air abraded as follows (n = 12): 1) 30-μm silica-modified Al₂O₃particles (Rocatec Soft); 2) 110-μm silica-modified Al₂O₃particles (Rocatec Plus); and 3) 120-μm Al₂O₃particles, followed by Rocatec Plus. Three specimens of each group were analyzed by x-ray diffraction (XRD) to assess the monoclinic phase content (%). The BFS test was performed in a mechanical testing machine (Instron 8874). Data (MPa) were analyzed by two-way ANOVA (grinding × airborne-particle abrasion and heat treatment × airborne-particle abrasion) and Tukey's post-hoc test (α = 0.05). The strength reliability was analyzed using the Weibull distribution., Results: Grinding significantly decreased the BFS of the non-heat-treated groups (p < 0.01). Within the ground groups, the previous heat treatment did not influence the BFS (p > 0.05). Air abrasion only influenced the BFS of the ground/heat-treated groups (p < 0.01). For the non-heat-treated groups, the grinding did not decrease the Weibull modulus (m), but it did decrease the characteristic strength (σ0). For Rocatec Soft and 120-μm Al₂O₃particles + Rocatec Plus, the heat-treated groups presented lower m and higher σ0 than the ground/non-heat-treated groups. The independent variables did not seem to influence phase transformation. Air-abraded surfaces presented higher monoclinic zirconia content than the as-sintered and ground surfaces, which exhibited similar content., Conclusion: Even under irrigation, grinding compromised the Y-TZP ceramic strength. The sintering of the veneering porcelain rendered the previous heat treatment recommended by the manufacturer unnecessary. Airborneparticle abrasion influenced the strength of heat-treated zirconia.
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- 2014
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36. Quantitative instruments used to assess children's sense of smell: a review article.
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Moura RG, Cunha DA, Gomes AC, and Silva HJ
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- Child, Child, Preschool, Equipment and Supplies, Humans, Infant, Infant, Newborn, Reproducibility of Results, Olfaction Disorders diagnosis, Smell physiology
- Abstract
Purpose: To systematically gather from the literature available the quantitative instruments used to assess the sense of smell in studies carried out with children., Research Strategy: The present study included a survey in the Pubmed and Bireme platforms and in the databases of MedLine, Lilacs, regional SciELO and Web of Science, followed by selection and critical analysis of the articles found and chosen., Selection Criteria: We selected original articles related to the topic in question, conducted only with children in Portuguese, English, and Spanish. We excluded studies addressing other phases of human development, exclusively or concurrently with the pediatric population; studies on animals; literature review articles; dissertations; book chapters; case study articles; and editorials., Data Analysis: A book report protocol was created for this study, including the following information: author, department, year, location, population/sample, age, purpose of the study, methods, and main results., Results: We found 8,451 articles by typing keywords and identifiers. Out of this total, 5,928 were excluded by the title, 2,366 by the abstract, and 123 after we read the full text. Thus, 34 articles were selected, of which 28 were repeated in the databases, totalizing 6 articles analyzed in this review., Conclusion: We observed a lack of standardization of the quantitative instruments used to assess children's sense of smell, with great variability in the methodology of the tests, which reduces the effectiveness and reliability of the results.
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- 2014
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37. Quantitative EEG evaluation in patients with acute encephalopathy.
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Braga AS, Assis BD, Ribeiro JT, Polla PM, Pereira BJ, Fonseca RG, and Betting LE
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- Acute Disease, Adolescent, Adult, Aged, Aged, 80 and over, Brain Diseases physiopathology, Female, Humans, Male, Middle Aged, Prognosis, Young Adult, Brain Diseases mortality, Electroencephalography methods
- Abstract
Objective: To investigate the use of quantitative EEG (qEEG) in patients with acute encephalopathies (AEs) and EEG background abnormalities., Method: Patients were divided into favorable outcome (group A, 43 patients) and an unfavorable outcome (group B, 5 patients). EEGLAB software was used for the qEEG analysis. A graphic of the spectral power from all channels was generated for each participant. Statistical comparisons between the groups were performed., Results: In group A, spectral analysis revealed spectral peaks (theta and alpha frequency bands) in 84% (38/45) of the patients. In group B, a spectral peak in the delta frequency range was detected in one patient. The remainder of the patients in both groups did not present spectral peaks. Statistical analysis showed lower frequencies recorded from the posterior electrodes in group B patients., Conclusion: qEEG may be useful in the evaluations of patients with AEs by assisting with the prognostic determination.
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- 2013
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38. The relationship between body composition, training and race performance in a group of Thoroughbred flat racehorses.
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Fonseca RG, Kenny DA, Hill EW, and Katz LM
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- Adipose Tissue, Animals, Female, Male, Body Composition physiology, Horses physiology, Physical Conditioning, Animal physiology, Running, Sports
- Abstract
Reasons for Performing Study: Few noninvasive measures associated with performance assessment are available for racehorse trainers. Evaluation of body composition of superior human sprinters has revealed a lower fat mass (FM), percentage (%) fat and greater fat-free mass (FFM), but to date there have been few studies evaluating this in racehorses., Objectives: To determine the effects of age, gender and training on body composition and the relationship between body composition, physiological measurements and performance in Thoroughbred racehorses., Methods: At 2, 5 and 8 months of training, rump fat thickness (RFT) was ultrasonographically measured in 1-, 2- and 3-year-old Thoroughbreds (n = 148), with FM, % fat and FFM calculated. Speed, heart rate, plasma lactate and serum creatine kinase concentrations were recorded during each fast work session. Training duration (number of training days) and intensity (number of fast work sessions) were collated for each training period. Retrospective racing performance was used to categorise horses as elite or nonelite., Results: FFM was greater in males (P = 0.006) at all training stages. There were no interactions between training duration, intensity, gender and age (P>0.05); all effects were linear. Training duration had a negative effect on RFT (P = 0.0002), FM (P<0.0001) and % fat (P<0.0001) and a positive effect on FFM (P = 0.01). Training intensity had a negative effect on RFT (P = 0.009), FM (P<0.0001), % fat (P<0.0001) and FFM (P<0.0001). FFM was greater for elite vs. nonelite horses at all training stages (P = 0.003), for males (P = 0.05) and females (P = 0.04) and for 2- (P = 0.002) and 3-year-olds (P = 0.02)., Conclusions: While age and training affect body composition, FFM is associated with performance., Potential Relevance: Body composition assessment may assist fitness and performance evaluation., (© 2012 EVJ Ltd.)
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- 2013
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39. Lack of kinin B₁ receptor potentiates leptin action in the liver.
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Fonseca RG, Sales VM, Ropelle E, Barros CC, Oyama L, Ihara SS, Saad MJ, Araújo RC, and Pesquero JB
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- Adipokines blood, Animals, Diet, High-Fat, Male, Mice, Mice, Knockout, Non-alcoholic Fatty Liver Disease, Receptor, Bradykinin B1 genetics, Receptor, Bradykinin B2 metabolism, Receptors, Leptin metabolism, Stearoyl-CoA Desaturase metabolism, Fatty Liver metabolism, Leptin metabolism, Liver metabolism, Receptor, Bradykinin B1 deficiency
- Abstract
Kinins B1 and B2 receptors (B1R and B2R) are classically associated with inflammation, but our group has recently demonstrated new roles for B1R in metabolism using a knockout model (B1 (-/-)). B1 (-/-) mice display improvement on leptin and insulin sensitivity and is protected from high fat diet (HFD)-induced obesity. Here, we evaluate the hepatic effects of the B1R ablation and its role on hepatic function. Despite no expression of hepatic B1R, HFD-induced hepatic lipid accumulation was lower than in control animals. B1 (-/-) mice also presented lower hepatic lipogenesis and SCD1 protein content in the liver. When stimulated with exogenous leptin, B1 (-/-) mice exhibited increased hepatic pJAK2. Similarly, leptin signaling was enhanced in the liver of ob/ob-B1 (-/-) mice, as demonstrated by increased levels of pSTAT3 compared to ob/ob. Plasma concentrations of intercellular adhesion molecule 1, fetuin A, leukemia inhibitory factor, tissue inhibitor of metalloprotease-1, resistin, and oncostatin M were reduced in B1 (-/-). Finally, B1 (-/-) mice have increased gene expression of hepatic B2 receptor, but no difference in leptin receptor expression. Our results show that B1 (-/-) mice are protected from non-alcoholic fatty liver disease (NAFLD) after HFD treatment. Since B1R expression was not observed in the liver after HFD, we propose that the cross talk between the adipose tissue and the liver, mainly through leptin, is an important factor contributing to the observed results. Besides that, several other inflammatory mediators already correlated with NAFLD or liver function were found to be altered in our model. Taken together, our data suggest that B1R plays an important role in hepatic steatosis development.
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- 2013
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40. The effect of different surface treatments on the shear bond strength of luting cements to titanium.
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Abi-Rached Fde O, Fonseca RG, Haneda IG, de Almeida-Júnior AA, and Adabo GL
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- Aluminum Oxide chemistry, Bisphenol A-Glycidyl Methacrylate chemistry, Carbon Compounds, Inorganic chemistry, Composite Resins chemistry, Dental Cements chemistry, Dental Etching methods, Dental Polishing methods, Dental Stress Analysis instrumentation, Humans, Materials Testing, Polyethylene Glycols chemistry, Polymethacrylic Acids chemistry, Shear Strength, Silanes chemistry, Silicon Compounds chemistry, Stress, Mechanical, Surface Properties, Temperature, Time Factors, Water chemistry, Dental Bonding, Dental Materials chemistry, Glass Ionomer Cements chemistry, Resin Cements chemistry, Titanium chemistry
- Abstract
Statement of Problem: Although titanium presents attractive physical and mechanical properties, there is a need for improving the bond at the titanium/luting cement interface for the longevity of metal ceramic restorations., Purpose: The purpose of this study was to evaluate the effect of surface treatments on the shear bond strength (SBS) of resin-modified glass ionomer and resin cements to commercially pure titanium (CP Ti)., Material and Methods: Two hundred and forty CP Ti cast disks (9.0 × 3.0 mm) were divided into 8 surface treatment groups (n=30): 1) 50 µm Al(2)O(3) particles; 2) 120 µm Al(2)O(3) particles; 3) 250 µm Al(2)O(3) particles; 4) 50 µm Al(2)O(3) particles + silane (RelyX Ceramic Primer); 5) 120 µm Al(2)O(3) particles + silane; 6) 250 µm Al(2)O(3) particles + silane; 7) 30 µm silica-modified Al(2)O(3) particles (Cojet Sand) + silane; and 8) 120 µm Al(2)O(3) particles, followed by 110 µm silica-modified Al(2)O(3) particles (Rocatec). The luting cements 1) RelyX Luting 2; 2) RelyX ARC; or 3) RelyX U100 were applied to the treated CP Ti surfaces (n=10). Shear bond strength (SBS) was tested after thermal cycling (5000 cycles, 5°C to 55°C). Data were analyzed by 2-way analysis of variance (ANOVA) and the Tukey HSD post hoc test (α=.05). Failure mode was determined with a stereomicroscope (×20)., Results: The surface treatments, cements, and their interaction significantly affected the SBS (P<.001). RelyX Luting 2 and RelyX U100 exhibited similar behavior for all surface treatments. For both cements, only the group abraded with 50 μm Al(2)O(3) particles had lower SBS than the other groups (P<.05). For RelyX ARC, regardless of silane application, abrasion with 50 μm Al(2)O(3) particles resulted in significantly lower SBS than abrasion with 120 μm and 250 μm particles, which exhibited statistically similar SBS values to each other. Rocatec + silane promoted the highest SBS for RelyX ARC. RelyX U100 presented the highest SBS mean values (P<.001). All groups showed a predominance of adhesive failure mode., Conclusions: The adhesive capability of RelyX Luting 2 and RelyX U100 on the SBS was decisive, while for RelyX ARC, mechanical and chemical factors were more influential., (Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.)
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- 2012
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41. MSTN genotypes in Thoroughbred horses influence skeletal muscle gene expression and racetrack performance.
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McGivney BA, Browne JA, Fonseca RG, Katz LM, Machugh DE, Whiston R, and Hill EW
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- Animals, Female, Gene Expression, Gene Expression Regulation, Genotype, Male, RNA, Messenger genetics, RNA, Messenger metabolism, Horses genetics, Motor Activity genetics, Muscle, Skeletal metabolism, Myostatin genetics, Physical Conditioning, Animal physiology
- Abstract
Myostatin, encoded by the MSTN gene, is a member of the TGF-β superfamily that regulates skeletal muscle development. A MSTN SNP significantly associated with Thoroughbred horse racing phenotypes has recently been identified as well as significant reductions in Thoroughbred skeletal muscle gene expression for three transcripts 400-1500 base pairs downstream of the MSTN gene following a period of training. Together, these findings indicate that MSTN genotypes may influence MSTN gene expression. To investigate this, MSTN mRNA expression was measured in biopsies from the middle gluteal muscle from 60 untrained yearling Thoroughbreds (C/C, n = 15; C/T, n = 28; T/T, n = 17) using two independent real-time qRT-PCR assays. MSTN gene expression was also evaluated in a subset (N = 33) of these animals using samples collected after a ten-month period of training. A significant association was observed between genotype and mRNA abundance for the untrained horses (assay I, P = 0.0237; assay II, P = 0.003559), with the C/C cohort having the highest MSTN mRNA levels, the T/T group the lowest levels and the C/T group intermediate levels. Following training, there was a significant decrease in MSTN mRNA (-3.35-fold; P = 6.9 × 10(-7) ), which was most apparent for the C/C cohort (-5.88-fold, P = 0.001). These data demonstrate the tight relationship between phenotype, genotype and gene expression at the MSTN gene in Thoroughbred racehorses., (© 2012 The Authors, Animal Genetics © 2012 Stichting International Foundation for Animal Genetics.)
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- 2012
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42. Effect of different airborne-particle abrasion/bonding agent combinations on the bond strength of a resin cement to a base metal alloy.
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Fonseca RG, Martins SB, de Oliveira Abi-Rached F, and Dos Santos Cruz CA
- Subjects
- Aluminum Oxide, Bisphenol A-Glycidyl Methacrylate, Dental Cements, Dental Stress Analysis, Materials Testing, Methacrylates, Particle Size, Polyethylene Glycols, Polymethacrylic Acids, Shear Strength, Silanes chemistry, Surface Properties, Thiones, Air Abrasion, Dental, Chromium Alloys, Dental Bonding, Resin Cements
- Abstract
Statement of Problem: Investigation of surface treatments to improve the bond of resin cements to metals may contribute to the longevity of metal ceramic restorations., Purpose: The purpose of this study was to evaluate the efficacy of surface treatments on the shear bond strength (SBS) of a resin cement to nickel-chromium (NiCr) alloy., Material and Methods: Eighty cast NiCr alloy disks (9 × 3 mm) were divided into 8 groups (n=10), which received 1 of the following surface treatments: 1) 50 µm Al(2)O(3) particles + silane; 2) 120 µm Al(2)O(3) + silane; 3) 30 µm silica-modified Al(2)O(3) (Cojet Sand) + silane; 4) 120 µm Al(2)O(3) followed by 110 µm silica-modified Al(2)O(3) (Rocatec) + silane; 5) 50 µm Al(2)O(3) + metal primer; 6) 120 µm Al(2)O(3) + metal primer; 7) 30 µm silica-modified Al(2)O(3) (Cojet Sand) + metal primer; and 8) 120 µm Al(2)O(3) followed by 110 µm silica-modified Al(2)O(3) (Rocatec) + metal primer. The silane was RelyX Ceramic Primer and the metal primer Alloy Primer. RelyX ARC resin cement was bonded to NiCr alloy surfaces. Specimens were thermally cycled before shear mode testing. Data (MPa) were analyzed by 1-way ANOVA and the Tukey test (α=.05). Failure mode was determined with a stereomicroscope (×20)., Results: The results revealed that surface treatment was significant (P<.001). There was no significant difference between 50 µm and 120 µm Al(2)O(3) particles, regardless of the bonding agent used (silane or metal primer). Cojet Sand provided lower SBS than Rocatec, both in the groups treated with silane (P<.001) and metal primer (P<.01). No significant difference was observed between silane and metal primer in the groups abraded with 50 µm and 120 µm Al(2)O(3) particles. Metal primer decreased the SBS of both Cojet Sand and Rocatec groups (P<.001). Rocatec + silane had the highest SBS and Cojet Sand + metal primer the lowest. All groups presented 100% adhesive failure., Conclusions: Particle size influenced SBS only in the groups abraded with silica-modified Al(2)O(3). The bonding agent did not affect SBS in the groups abraded with Al(2)O(3). Alloy Primer was not chemically compatible with silica-modified Al(2)O(3). Both mechanical (particle size) and chemical (silica/silane interaction) factors contributed to the high SBS of Rocatec + silane., (Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.)
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- 2012
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43. Efficacy of air-abrasion technique and additional surface treatment at titanium/resin cement interface.
- Author
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Fonseca RG, Haneda IG, Almeida-Júnior AA, de Oliveira Abi-Rached F, and Adabo GL
- Subjects
- Adhesiveness, Aluminum Oxide chemistry, Bisphenol A-Glycidyl Methacrylate chemistry, Dental Cements chemistry, Dental Stress Analysis instrumentation, Humans, Materials Testing, Methacrylates chemistry, Particle Size, Polyethylene Glycols chemistry, Polymethacrylic Acids chemistry, Shear Strength, Silanes chemistry, Silicon Dioxide chemistry, Stress, Mechanical, Surface Properties, Temperature, Time Factors, Dental Bonding, Dental Etching methods, Dental Materials chemistry, Resin Cements chemistry, Titanium chemistry
- Abstract
Purpose: To evaluate the effect of surface treatments on the shear bond strength (SBS) of a resin cement to commercially pure titanium (CP Ti)., Materials and Methods: Two hundred cast CP Ti disks were divided into 5 groups (n = 40), which were treated with one of the following air-abrasion techniques: (1) 50-µm Al2O3 particles; (2) 120-µm Al2O3 particles; (3) 250-µm Al2O3 particles; (4) 30-µm silica-modified Al2O3 particles (Cojet Sand); (5) 50-µm Al2O3 particles followed by 110-µm silica-modified Al2O3 particles (Rocatec Plus). For each air-abrasion technique, the following additional surface treatments were used (n = 10): (1) none; (2) adhesive Adper Single Bond 2; (3) silane RelyX Ceramic Primer; (4) silane plus adhesive. RelyX ARC resin cement was bonded to CP Ti surfaces. All specimens were thermocycled (5,000 cycles) before being tested in shear mode. Data (MPa) were analyzed using two-way ANOVA and Tukey's test (α = 0.05). Failure mode was determined with a stereomicroscope (20X)., Results: The results revealed that the air-abrasion technique (p < 0.001), additional surface treatment (p < 0.001) and their interaction were significant (p < 0.001). Except for the 50-µm Al2O3 + adhesive group, 250-µm Al2O3 particles promoted significantly higher SBS than 50-µm Al2O3 particles (p < 0.001), while Rocatec Plus provided bond strengths that were similar to or higher than those of Cojet Sand. Of the additional surface treatments, the adhesive provided the best results in combination with the 3 air-abrasion techniques (50-µm, 120-µm, and 250-µm Al2O3), whereas in the groups abraded with silica-modified Al2O3 particles (Cojet Sand and Rocatec Plus), the best results were obtained with additional silane. The two combinations that promoted the highest SBS were 250-µm Al2O3 + adhesive and Rocatec Plus + silane. All groups showed 100% adhesive failure., Conclusion: The selection of the best additional surface treatment varied according to the air-abrasion technique. Particle size was the decisive factor in determining the bond strength when micromechanical retention was the only bonding mechanism. When both mechanisms were present, in addition to particle size, the material applied as the additional surface treatment also contributed to determining the bond strength.
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- 2012
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44. Intracellular proteolysis of kininogen by malaria parasites promotes release of active kinins.
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Bagnaresi P, Barros NM, Assis DM, Melo PM, Fonseca RG, Juliano MA, Pesquero JB, Juliano L, Rosenthal PJ, Carmona AK, and Gazarini ML
- Subjects
- Animals, Calcium metabolism, Endothelial Cells drug effects, Endothelial Cells metabolism, Guinea Pigs, Humans, Ileum drug effects, Mass Spectrometry, Muscle Contraction drug effects, Plasmodium chabaudi metabolism, Plasmodium falciparum metabolism, Proteolysis, Cysteine Endopeptidases metabolism, Kininogens metabolism, Kinins metabolism, Plasmodium chabaudi enzymology, Plasmodium falciparum enzymology
- Abstract
Background: The malaria burden remains a major public health concern, especially in sub-Saharan Africa. The complex biology of Plasmodium, the apicomplexan parasite responsible for this disease, challenges efforts to develop new strategies to control the disease. Proteolysis is a fundamental process in the metabolism of malaria parasites, but roles for proteases in generating vasoactive peptides have not previously been explored., Results: In the present work, it was demonstrated by mass spectrometry analysis that Plasmodium parasites (Plasmodium chabaudi and Plasmodium falciparum) internalize and process plasma kininogen, thereby releasing vasoactive kinins (Lys-BK, BK and des-Arg9-BK) that may mediate haemodynamic alterations during acute malaria. In addition, it was demonstrated that the P. falciparum cysteine proteases falcipain-2 and falcipain-3 generated kinins after incubation with human kininogen, suggesting that these enzymes have an important role in this process. The biologic activity of peptides released by Plasmodium parasites was observed by measuring ileum contraction and activation of kinin receptors (B1 and B2) in HUVEC cells; the peptides elicited an increase in intracellular calcium, measured by Fluo-3 AM fluorescence. This effect was suppressed by the specific receptor antagonists Des-Arg9[Leu8]-BK and HOE-140., Conclusions: In previously undescribed means of modulating host physiology, it was demonstrated that malaria parasites can generate active kinins by proteolysis of plasma kininogen.
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- 2012
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45. MSTN genotype (g.66493737C/T) association with speed indices in Thoroughbred racehorses.
- Author
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Hill EW, Fonseca RG, McGivney BA, Gu J, MacHugh DE, and Katz LM
- Subjects
- Animals, Female, Genetic Variation, Horses, Male, Sports physiology, Genotype, Myostatin genetics, Physical Conditioning, Animal physiology, Running physiology
- Abstract
Sequence variation at the equine myostatin gene (MSTN) locus has previously been shown to have a singular genomic influence on optimum race distance in Thoroughbred racehorses. Myostatin, encoded by the MSTN gene, is a member of the TGF-β superfamily that regulates skeletal muscle development in a range of mammalian species including the horse. In the Thoroughbred, the C-allele at the g.66493737C/T SNP has been found at significantly higher frequency in subgroups of the population that are suited to fast, short distance, sprint races and also influences body composition phenotypes. We investigated the influence of the g.66493737C/T SNP on speed indexes measured in a cohort of n = 85 Thoroughbred horses-in-training. We found significant associations between genotypes at the g.66493737C/T SNP and all measured speed variables: Dist(6) [distance travelled during 6 s before and after maximal velocity (V(max)); P = 0.0040], V(maxt) (duration at V(max); P = 0.0249), V(max) (P = 0.0265), Dist(6b) (distance travelled during 6 s before V(max); P = 0.0032), and Dist(6a)(distance travelled during 6 s after V(max); P = 0.0317). For each measure, horses with the C/C and C/T genotypes outperformed T/T horses, indicating the requirement for at least one C-allele to improve speed. For the most significantly associated variables (Dist(6) and Dist(6b)) the C/C cohort performed better than the T/T cohort with the heterozygotes intermediate, indicating a dose-dependent manifestation. These findings clearly indicate that variation at the MSTN gene influences speed in Thoroughbred horses.
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- 2012
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46. Kinin B1 receptor in adipocytes regulates glucose tolerance and predisposition to obesity.
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Mori MA, Sales VM, Motta FL, Fonseca RG, Alenina N, Guadagnini D, Schadock I, Silva ED, Torres HA, dos Santos EL, Castro CH, D'Almeida V, Andreotti S, Campaña AB, Sertié RA, Saad MJ, Lima FB, Bader M, and Pesquero JB
- Subjects
- Animals, Gene Expression Regulation, Genetic Predisposition to Disease, Glucose Transporter Type 4 metabolism, Insulin metabolism, Insulin Resistance genetics, Male, Mice, Mice, Knockout, Obesity genetics, Receptor, Bradykinin B1 genetics, Adipocytes metabolism, Glucose metabolism, Kinins metabolism, Obesity metabolism, Receptor, Bradykinin B1 metabolism
- Abstract
Background: Kinins participate in the pathophysiology of obesity and type 2 diabetes by mechanisms which are not fully understood. Kinin B(1) receptor knockout mice (B(1) (-/-)) are leaner and exhibit improved insulin sensitivity., Methodology/principal Findings: Here we show that kinin B(1) receptors in adipocytes play a role in controlling whole body insulin action and glucose homeostasis. Adipocytes isolated from mouse white adipose tissue (WAT) constitutively express kinin B(1) receptors. In these cells, treatment with the B(1) receptor agonist des-Arg(9)-bradykinin improved insulin signaling, GLUT4 translocation, and glucose uptake. Adipocytes from B(1) (-/-) mice showed reduced GLUT4 expression and impaired glucose uptake at both basal and insulin-stimulated states. To investigate the consequences of these phenomena to whole body metabolism, we generated mice where the expression of the kinin B(1) receptor was limited to cells of the adipose tissue (aP2-B(1)/B(1) (-/-)). Similarly to B(1) (-/-) mice, aP2-B(1)/B(1) (-/-) mice were leaner than wild type controls. However, exclusive expression of the kinin B(1) receptor in adipose tissue completely rescued the improved systemic insulin sensitivity phenotype of B(1) (-/-) mice. Adipose tissue gene expression analysis also revealed that genes involved in insulin signaling were significantly affected by the presence of the kinin B(1) receptor in adipose tissue. In agreement, GLUT4 expression and glucose uptake were increased in fat tissue of aP2-B(1)/B(1) (-/-) when compared to B(1) (-/-) mice. When subjected to high fat diet, aP2-B(1)/B(1) (-/-) mice gained more weight than B(1) (-/-) littermates, becoming as obese as the wild types., Conclusions/significance: Thus, kinin B(1) receptor participates in the modulation of insulin action in adipocytes, contributing to systemic insulin sensitivity and predisposition to obesity.
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- 2012
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47. B1 and B2 kinin receptor participation in hyperproliferative and inflammatory skin processes in mice.
- Author
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Pietrovski EF, Paludo KS, Mendes DA, Guimarães Fde S, Veiga SS, Buchi Dde F, Fonseca RG, Zampronio AR, Bader M, Pesquero JB, Ferreira J, Otuki MF, and Cabrini DA
- Subjects
- Administration, Topical, Animals, Cell Proliferation, Dioxoles pharmacology, Female, Inflammation, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Proliferating Cell Nuclear Antigen biosynthesis, Quinolines pharmacology, Sulfonamides pharmacology, Tetradecanoylphorbol Acetate pharmacology, Receptor, Bradykinin B1 metabolism, Receptor, Bradykinin B2 metabolism, Skin Diseases pathology
- Abstract
Background: Kinins are released during dermal injury and inflammation and seem to contribute to the pathogenesis of cutaneous diseases., Objective: Participation of kinins in skin inflammatory process was evaluated using knockout mice and non-peptide kinin receptor antagonists., Methods: Chronic skin inflammation was induced by multiple applications of TPA in mice ear., Results: The B(2) knockout mice (B(2)(-/-)) showed a significant increase of ear weight (23 ± 10%) and epidermal cellular hyperproliferation and acanthosis formation upon histological analysis when compared with wildtype mice. Also, evaluation of PCNA levels by Western blot and immunohistochemistry confirmed the increase in the epidermis hyperproliferation in the ear skin of B(2)(-/-) mice. In contrast, no modification in these parameters was detected in B(1) knockout mice (B(1)(-/-)). However, mice lacking both kinin receptors (B(1)B(2)(-/-)) presented a considerable reduction of epidermis thickness and in PCNA levels. Following the establishment of skin inflammation (5th day of TPA application) treatment with the non-peptide antagonists SSR 240612 (B(1) receptor antagonist), FR 173657 (B(2) receptor antagonist), or SSR 240612 plus FR 173657 topically applied, caused a significant inhibition of ear weight (20 ± 5%, 34 ± 4% and 32 ± 6%, respectively). In the histological analysis, the antagonists produced a reduction in epidermal hyperplasia and acanthosis formation; but the treatment with a combination of the two antagonists did not increase efficacy., Conclusion: Kinin receptors seem to be involved in the control of the keratinocyte hyperproliferative process, and non-peptide kinin receptor antagonists may be useful tools in the treatment of hyperproliferative skin disorders., (Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.)
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- 2011
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48. mRNA expression of genes regulating oxidative phosphorylation in the muscle of beef cattle divergently ranked on residual feed intake.
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Kelly AK, Waters SM, McGee M, Fonseca RG, Carberry C, and Kenny DA
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- Animal Feed, Animals, Cattle, Cyclooxygenase 2 genetics, Eating physiology, Ion Channels genetics, Mitochondrial Proteins genetics, Phenotype, Polymerase Chain Reaction, Uncoupling Protein 3, Muscle, Skeletal metabolism, Oxidative Phosphorylation
- Abstract
Our objective was to evaluate the effects of phenotypic ranking on residual feed intake (RFI) on the transcription of genes 1) involved in the respiratory chain complex and 2) coding for transcriptional factors regulating mitochondrial biogenesis, across two contrasting diet types. Beef heifers (n = 86) fed a diet comprising 70:30 concentrate-corn silage [low forage (LF)] over a 82-day period were ranked on RFI. The 10 highest (feed inefficient, high-RFI) and 10 lowest (feed efficient, low-RFI) ranking animals were selected for the current study. Biopsies of the M. longissimus dorsi were harvested following initial selection (LF diet) and again following a 6 wk period while the animals were offered a high-forage (HF) grass silage-only diet. Real-time PCR was used to quantify mRNA transcripts of 17 genes associated with cellular energetic efficiency. The mRNA expression of UCP3 tended to be upregulated (2.2-fold, P = 0.06) for the high-RFI compared with the low-RFI animals. mRNA transcripts coding for the transcription factor PGC-1α was 1.7-fold higher (P = 0.01) in low compared with high-RFI animals. A phenotype × diet interaction was evident for the abundance of ANT1 mRNA transcript, with greater (P = 0.04) expression levels detected in the low-RFI phenotype during the HF period, but no difference (P = 0.50) between phenotypes during the LF period. A phenotype × diet interaction was also evident for COX II with greater expression levels detected (P = 0.04) in the low compared with the high RFI phenotype while on LF but not the HF diet (P = 0.22). These data suggest an association between cellular energetic efficiency and RFI in cattle.
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- 2011
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49. Moderate and high intensity sprint exercise induce differential responses in COX4I2 and PDK4 gene expression in Thoroughbred horse skeletal muscle.
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Hill EW, Eivers SS, McGivney BA, Fonseca RG, Gu J, Smith NA, Browne JA, MacHugh DE, and Katz LM
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- Animals, Electron Transport Complex IV genetics, Exercise Test, Female, Male, Muscle, Skeletal metabolism, Protein Kinases genetics, RNA, Messenger genetics, RNA, Messenger metabolism, Electron Transport Complex IV metabolism, Gene Expression Regulation physiology, Horses genetics, Horses physiology, Physical Conditioning, Animal physiology, Protein Kinases metabolism
- Abstract
Reasons for Performing Study: The role of molecular signalling pathways in the phenotypic adaptation of skeletal muscle to different exercise stimuli in the Thoroughbred horse has not been reported previously., Objective: To examine CKM, COX4I1, COX4I2 and PDK4 gene expression following high intensity sprint and moderate intensity treadmill exercise stimuli in skeletal muscle of Thoroughbred horses., Materials and Methods: Two groups of trained 3-year-old Thoroughbred horses participated. Group A (n = 6 females, n = 3 males) participated in an incremental step test (moderate intensity) to fatigue or HR(max) on a Sato high speed treadmill (distance = 5418.67 m ± 343.21). Group B (n = 8 females) participated in routine 'work' (sprint) on an all-weather gallop (distance = 812.83 m ± 12.53). Biopsy samples were obtained from the gluteus medius pre-exercise (T(0)), immediately post exercise (T(1)) and 4 h post exercise (T(2)). For physiological relevance venous blood samples were collected to measure plasma lactate and creatine kinase concentrations. Changes in mRNA expression were determined by quantitative real-time RT-PCR for creatine kinase muscle (CKM), cytochrome c oxidase subunit IV isoform 1 (COX4I1), cytochrome c oxidase subunit IV isoform 2 (COX4I2) and pyruvate dehydrogenase kinase, isozyme 4 (PDK4) genes. Statistical significance (α < 0.05) was determined using Student's t tests., Results: COX4I2 mRNA expression decreased significantly in Group A and remained unchanged in Group B between T(0) vs. T(2) (-1.7-fold, P = 0.017; -1.0-fold, P = 0.859). PDK4 mRNA expression increased significantly in Group B but not in Group A between T(0) vs. T(1) (3.8-fold, P = 0.039; 1.4-fold, P = 0.591). There were no significant changes in the expression in CKM or COX4I1 mRNA abundance in either group., Conclusions: Different exercise protocols elicit variable transcriptional responses in key exercise relevant genes in equine skeletal muscle due to variation in metabolic demand., (© 2010 EVJ Ltd.)
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- 2010
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50. The association of various speed indices to training responses in Thoroughbred flat racehorses measured with a global positioning and heart rate monitoring system.
- Author
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Fonseca RG, Kenny DA, Hill EW, and Katz LM
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- Animals, Female, Male, Monitoring, Physiologic methods, Telemetry, Geographic Information Systems, Heart Rate physiology, Horses physiology, Monitoring, Physiologic instrumentation, Physical Conditioning, Animal physiology
- Abstract
Reasons for Performing Study: Fitness assessment can be challenging. The use of global positioning systems (GPS) with heart rate (HR) monitors has been promising; however, evaluation of speed parameters during training has not been reported., Objectives: To evaluate speed indices during training in Thoroughbreds using a GPS-HR monitor., Methods: Thoroughbreds (n = 102) were assessed during training with data collected each work day (WD; sprinting). Speed indices evaluated included maximal velocity (V(max)), duration at V(max) (V(maxt)), acceleration rate (m/s(2)) from 800 m to V(max) (Acc800-V(max)), the distance (m) 6 (V(maxD6)) and 12 (V(maxD12)) s before (acceleration [a]) and after (deceleration [d]) V(max) and the deceleration rate from V(max) to the finish (V(maxDFd)). Blood for plasma lactate ([LA]) and creatine kinase ([CK]) measurements were taken before (T(0)), 5 mins (T(1)) and 6 h after exercise (T(2)). WD accumulation, jockey, gallop condition, horse gender, age, total distance covered (DistT), maximum HR (HR(max)), velocity at 200 beats/min (V(200)) and velocity at maximum HR (VHR(max)) for each WD were evaluated for associations with [LA], [CK], speed indices and racing performance. Data were analysed by repeated measures ANOVA with P < 0.05 significant., Results: No speed parameter clearly changed with training. Gallop condition affected V(max), V(maxt) and all distances covered with V(max) and distances increasing and V(maxt) decreasing as gallop surface became firmer. Jockey influenced V(max), V(maxD6a) and all decelerations, while DistT was inversely associated with Acc800-V(max), HR(max) and V(200) and positively associated with V(max), all accelerations and decelerations. [LA] at T(1) was positively associated with DistT and V(maxDFd)., Conclusions: Speed parameters did not change with training but were affected by jockey, gallop condition and exercise distance. This information may help to modify training to maximise fitness, minimise injury and choose distances best suited for individuals., (© 2010 EVJ Ltd.)
- Published
- 2010
- Full Text
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