RESUMO
OBJECTIVES: To minimize the tooth sensitivity caused by in-office bleaching, many dentists use non-steroidal anti-inflammatory drugs and topical desensitizing gels containing potassium nitrate and sodium fluoride. This study aimed to evaluate the influence of these substances on inflammation and the expression of substance P and calcitonin gene-related peptide in pulp nerve fibers. MATERIALS AND METHODS: Seventy-two rats were divided into 6 groups as follows: GI, control; GII, only dental bleaching; GIII, only ibuprofen; GIV, ibuprofen administered 30 minutes before and after the bleaching treatment and every 12 hours until the analysis; GV, only topical application of a desensitizing agent; and GVI, topical application of a desensitizing agent before dental bleaching. Placebo gel was applied to the upper left jaw and the bleaching agent was applied to the upper right jaw in all groups. Subsequently, the groups were divided into 3 subgroups based on the time of analysis: 0, 24, and 48 hours after bleaching (n = 8). The rats were euthanized and the maxillae were processed and evaluated by histopathological and immunohistochemical analyses. The data were analyzed using the Kruskal-Wallis test, followed by the Dunn test (p < 0.05). RESULTS: In the bleaching groups, the inflammatory process and expression of neuropeptides decreased over time. The animals in which a desensitizing agent was applied showed better results within 24 hours. CONCLUSIONS: The use of a desensitizing agent had positive effects on inflammation and pain-related neuropeptide expression, minimizing the painful effects of dental bleaching treatment.
RESUMO
AIM: To compare the effect of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser at different irradiation parameters and acid etching on the shear bond strength (SBS) of orthodontic brackets to enamel. MATERIALS AND METHODS: Forty bovine incisors were randomly distributed into groups (n = 10): GI: 37% phosphoric acid etching; GII: Er,Cr:YSGG laser etching 19.1 J/cm2; GIII: Er,Cr:YSGG, 29.3 J/cm2; and GIV: Er,Cr:YSGG, 42.4 J/cm2. After treatments, metallic brackets were bonded using Transbond XT adhesive system. After light curing, the samples were subjected to 500 thermal cycles, debonded with a universal testing machine, and the SBS values were recorded. After debonding, surface morphology was evaluated using scanning electron microscopy (SEM) and optical coherence tomography (OCT). The values of SBS testing were analyzed by one-way analysis of variance (ANOVA) and Tukey post hoc test, at 5% significance level. RESULTS: The mean SBS values of GI, GII, GIII, and GIV groups were 6.2 ± 1.7 MPa, 4.6 ± 2.5 MPa, 7.0 ± 2.2 MPa, and 8.0 ± 3.6 MPa, respectively. Laser irradiation promoted rough surfaces in all parameters used, and the OCT analysis revealed higher optical changes on lased groups when compared with phosphoric acid. CONCLUSION: Er,Cr:YSGG laser irradiation operated at 42.4 J/cm2 and 29.3 J/cm2 is a better alternative for etching enamel prior to the orthodontic treatment than the phosphoric acid. CLINICAL SIGNIFICANCE: Er,Cr:YSGG laser irradiation is better than the phosphoric acid for etching enamel prior to the orthodontic treatment because laser irradiation promotes similar SBSs and preventing demineralization around orthodontic brackets.
Assuntos
Colagem Dentária , Lasers de Estado Sólido , Braquetes Ortodônticos , Animais , Bovinos , Esmalte Dentário , Propriedades de SuperfícieRESUMO
AIM: The aim of this study is to evaluate the effect of silane (Si) application and different adhesive systems on the bond strength of composite resin repair. MATERIALS AND METHODS: One hundred composite truncated cone-shaped specimens were prepared and submitted to 5,000 thermal cycles to simulate existing restorations. Their top surfaces were airborne particle abraded with aluminum oxide, etched with phosphoric acid, and divided into two groups (n = 50) with or without Si application. Each group was divided into five subgroups (n = 10) according to the adhesive system applied: Solobond Plus Primer and Adhesive (SPA)-two-bottle, Solobond Plus adhesive (SA), Admira Bond (A)-one bottle, Futurabond DC (FDC)-self-etch, and Futurabond M (FM)-self-etch. New composite resin was applied over the bonded area. A control group was prepared to evaluate the cohesive strength of the composite resin. Specimens were submitted to tensile stress. Data were analyzed with two-way analysis of variance (ANOVA), and the Tukey and Dunnett tests. RESULTS: Si application reduced the bond strength of all adhesives (p = 0.001). Groups SA and SPA showed higher bond strengths in relation to other groups (p = 0.01). Groups FDC + Si, FM, FM + Si, and A + Si showed smaller mean bond strength values than that of the control group (p < 0.05). CONCLUSION: Previous Si application reduced bond strength values. The two-bottle adhesive showed better results than one-bottle or self-etching systems for composite resin repairs. CLINICAL SIGNIFICANCE: The kind of adhesive system applied for composite resin repairs has a great influence on bond strength values. The use of Si in this situation is not recommended.
Assuntos
Colagem Dentária , Silanos , Condicionamento Ácido do Dente , Resinas Compostas , Cimentos Dentários , Análise do Estresse Dentário , Teste de Materiais , Cimentos de Resina , Propriedades de Superfície , Resistência à TraçãoRESUMO
We determined peripheral blood (PB) and biopsy (Bx) RNA expression signatures in a Brazilian and US cohort of kidney transplant patients. Phenotypes assigned by precise histology were: acute rejection (AR), interstitial fibrosis/tubular atrophy/chronic rejection (CR), excellent functioning transplants (TX), and glomerulonephritis recurrence (GN). Samples were analyzed on microarrays and profiles from each cohort were cross-validated on the other cohort with similar phenotypes. We discovered signatures for each tissue: (1) AR vs TX, (2) CR vs TX, and (3) GN vs TX using the Random Forests algorithm. We validated biopsies signatures of AR vs TX (area under the curve [AUC] 0.97) and CR vs TX (AUC 0.87). We also validated both PB and Bx signatures of AR vs TX and CR vs TX with varying degrees of accuracy. Several biological pathways were shared between AR and CR, suggesting similar rejection mechanisms in these 2 clinical phenotypes. Thus, we identified gene expression signatures for AR and CR in transplant patients and validated them in independent cohorts of significantly different racial/ethnic backgrounds. These results reveal that there are strong unifying immune mechanisms driving transplant diseases and identified in the signatures discovered in each cohort, suggesting that molecular diagnostics across populations are feasible despite ethnic and environmental differences.
Assuntos
Biomarcadores/análise , Etnicidade/genética , Rejeição de Enxerto/diagnóstico , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Leucócitos Mononucleares/metabolismo , Transcriptoma , Adolescente , Adulto , Idoso , Biópsia , Estudos de Coortes , Feminino , Seguimentos , Perfilação da Expressão Gênica , Rejeição de Enxerto/sangue , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto JovemRESUMO
AIM: The purpose of this study was to evaluate the influence of widening the apical root canal preparation (RCP) on the efficiency of different ethylenediaminetetraacetic acid (EDTA) agitation protocols on smear layer removal: EDTA; EDTA + Easy Clean in rotary movement (ECROT); EDTA + Easy Clean in reciprocating movement (ECREC); and EDTA + Passive ultrasonic irrigation (PUI). MATERIALS AND METHODS: A total of 80 mandibular premolars had their crowns sectioned and then were divided into two groups according to widening: size 25 or 40, 0.08 taper. Sequentially they were once again allocated to subgroups according to the agitation protocol performing eight experimental groups (n = 10). Ten additional teeth were prepared for controls (C+/C-). The specimens were then submitted to the cleaning protocols and thereafter cleaved and microphotographed by variable pressure scanning electron microscopy (SEM) at previously determined points along their root thirds (750*). Scores were attributed to the images, and data were analyzed by the Kruskal-Wallis, Student-Newman-Keuls and Friedman tests. RESULTS: A higher widening was observed to have a positive influence on cleaning efficiency offering significant differences in global and apical third evaluations (p < 0.05). Relative to the agitation, significant differences were observed mainly in the apical third, with PUI and ECROT providing the best results (p < 0.05); no difference for C+ was observed when higher widening was employed. CONCLUSION: A greater widening of the apical third provided a significant improvement in the action of the agitation/activation protocols. Moreover, the PUI and ECROT activation methods were shown to be superior to the use of EDTA solely, particularly in the apical third. CLINICAL SIGNIFICANCE: The findings of this study reinforce the need for clinical use of additional methods to complement cleaning. Therefore, it is important for professionals to have knowledge and command of these protocols to obtain more satisfactory results.
Assuntos
Cavidade Pulpar/ultraestrutura , Ácido Edético/administração & dosagem , Microscopia Eletrônica de Varredura , Irrigantes do Canal Radicular/administração & dosagem , Preparo de Canal Radicular/métodos , Irrigação Terapêutica/métodos , Ápice Dentário , Dente Pré-Molar , Humanos , Mandíbula , Camada de Esfregaço , UltrassomRESUMO
AIM: This research focused on the results of the cross-validation program related with the performance of a Cuban novel low-cost real-time quantitative polymerase chain reaction (qPCR) assay for hepatitis B virus (HBV) quantification developed by the Therapeutic Vaccine against Hepatitis B Department, Vaccines Division, Center for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba. MATERIALS AND METHODS: Dilution series with the plasmid standard at concentrations of 900,000 to 0.09 copies/reaction (c/r) were made for each PCR instrument. The mean cycles threshold (Ct) values and PCR efficiency were compared among the cyclers. Hepatitis B virus-positive serum samples were used for the calculation of reproducibility of the HBV assay. Biotecon Diagnostics (BCD) also ordered the oligo sequences from a second supplier and compared the PCR performance to those provided from the CIGB. RESULTS: All PCR cyclers were able to detect concentrations up to 0.09 c/r. However, below the concentration of 9 c/r, the variation of results increased within and between the cyclers. The PCR efficiency showed satisfying results. The overall coefficient of variation (CV) cycler values were 1.29 and 0.91% for M6 and M19 respectively. No significance was observed between the different primer suppliers. CONCLUSION: The HBV assay was performed with a good concordance between the five real-time instruments from different suppliers. The HBV assay was also performed with a high reproducibility for samples with a high and a low viral load. The HBV assay is robust against different primer suppliers.How to cite this article: Aguiar J, Silva JA, García G, Guillén G, Aguilar JC. Cross-validation Studies of a Novel Low-cost Hepatitis B Virus Quantitative Polymerase Chain Reaction System. Euroasian J Hepato-Gastroenterol 2018;8(1):38-41.
RESUMO
Introdução: Metalúrgicos compõem uma população de risco pela sua exposição ocupacional a toxicantes, como metais pesados, gases, hidrocarbonetos aromáticos e silicato. Objetivo: Avaliar a existência de efeitos biológicos em trabalhadores expostos a toxicantes de vários setores de uma metalúrgica de Caxias do Sul, Rio Grande do Sul. Método: Foi realizado um estudo transversal com 31 trabalhadores de 10 setores em que foi aplicado um questionário sobre hábitos ocupacionais e de vida. Exames hematológicos e toxicológicos foram comparados com os resultados do questionário. Resultados: 19,4% (n=6) dos trabalhadores não usaram todos os equipamentos de proteção individual (EPIs). Foi possível observar diminuição dos parâmetros do eritrograma e alterações na série branca, como leucocitose, neutrofilia e eosinofilia, e no chumbo sérico. Evidenciaram-se valores diminuídos na série vermelha e leucocitose dos trabalhadores que não faziam uso adequado dos EPIs. Quando avaliado o setor de trabalho, pôde-se evidenciar as seguintes associações significativas: fumantes e neutrofilia (p=0,000); setor da moldagem e leucocitose (p=0,023) e eosinofilia (p=0,007); mais de 10 anos de trabalho e leucocitose (p=0,008). Conclusões: Os dados sugerem que o tempo de trabalho, o tipo de exposição e o uso de EPIs podem alterar exames laboratoriais
Background: Metallurgical workers are a high-risk population as a function of their occupational exposure to toxicants, such as heavy metals, aromatic hydrocarbons and silicate. Objective: To investigate the occurrence of biological effects among workers exposed to toxicants in various areas of a metallurgical company in Caxias do Sul, Rio Grande do Sul, Brazil. Methods: Cross-sectional study with 31 workers from 10 areas who responded a questionnaire on occupational and lifestyle habits. Blood and toxicology tests were compared to the questionnaire results. Results: About 19.4% (n=6) of the sample did not use all the required personal protective equipment (PPE). Reduction of red blood cell parameters and leukocyte abnormalities were found, including leukocytosis, neutrophilia and eosinophilia, as well as in the blood lead levels. The following significant associations were found on analysis per work area: smoking and neutrophilia (p=0.000); work in the mold section and leukocytosis (p=0.023) and eosinophilia (p=0.007); and more than 10 years of work and leukocytosis (p=0.008). Conclusions: The data suggest that length of work, type of exposure and use of PPE might cause changes in the results of laboratory tests
Assuntos
Humanos , Exposição Ocupacional/efeitos adversos , Pesquisa , Equipamento de Proteção Individual , Indústria Metalúrgica , Estudos TransversaisRESUMO
Graft survival after small bowel transplantation remains impaired due to acute cellular rejection (ACR), the leading cause of graft loss. Although it was shown that the number of enteroendocrine progenitor cells in intestinal crypts was reduced during mild ACR, no results of Paneth and intestinal stem cells localized at the crypt bottom have been shown so far. Therefore, we wanted to elucidate integrity and functionality of the Paneth and stem cells during different degrees of ACR, and to assess whether these cells are the primary targets of the rejection process. We compared biopsies from ITx patients with no, mild, or moderate ACR by immunohistochemistry and quantitative PCR. Our results show that numbers of Paneth and stem cells remain constant in all study groups, whereas the transit-amplifying zone is the most impaired zone during ACR. We detected an unchanged level of antimicrobial peptides in Paneth cells and similar numbers of Ki-67+ IL-22R+ stem cells revealing cell functionality in moderate ACR samples. We conclude that Paneth and stem cells are not primary target cells during ACR. IL-22R+ Ki-67+ stem cells might be an interesting target cell population for protection and regeneration of the epithelial monolayer during/after a severe ACR in ITx patients.
Assuntos
Rejeição de Enxerto/fisiopatologia , Sobrevivência de Enxerto , Intestino Delgado/fisiopatologia , Intestino Delgado/transplante , Transplante de Órgãos/efeitos adversos , Celulas de Paneth/citologia , Células-Tronco/citologia , Adolescente , Adulto , Feminino , Seguimentos , Rejeição de Enxerto/etiologia , Humanos , Masculino , Celulas de Paneth/metabolismo , Prognóstico , Fatores de Risco , Células-Tronco/metabolismo , Adulto JovemRESUMO
BACKGROUND: Metallurgical workers are a high-risk population as a function of their occupational exposure to toxicants, such as heavy metals, aromatic hydrocarbons and silicate. OBJECTIVE: To investigate the occurrence of biological effects among workers exposed to toxicants in various areas of a metallurgical company in Caxias do Sul, Rio Grande do Sul, Brazil. METHODS: Cross-sectional study with 31 workers from 10 areas who responded a questionnaire on occupational and lifestyle habits. Blood and toxicology tests were compared to the questionnaire results. RESULTS: About 19.4% (n=6) of the sample did not use all the required personal protective equipment (PPE). Reduction of red blood cell parameters and leukocyte abnormalities were found, including leukocytosis, neutrophilia and eosinophilia, as well as in the blood lead levels. The following significant associations were found on analysis per work area: smoking and neutrophilia (p=0.000); work in the mold section and leukocytosis (p=0.023) and eosinophilia (p=0.007); and more than 10 years of work and leukocytosis (p=0.008). CONCLUSIONS: The data suggest that length of work, type of exposure and use of PPE might cause changes in the results of laboratory tests.
INTRODUÇÃO: Metalúrgicos compõem uma população de risco pela sua exposição ocupacional a toxicantes, como metais pesados, gases, hidrocarbonetos aromáticos e silicato. OBJETIVO: Avaliar a existência de efeitos biológicos em trabalhadores expostos a toxicantes de vários setores de uma metalúrgica de Caxias do Sul, Rio Grande do Sul. MÉTODO: Foi realizado um estudo transversal com 31 trabalhadores de 10 setores em que foi aplicado um questionário sobre hábitos ocupacionais e de vida. Exames hematológicos e toxicológicos foram comparados com os resultados do questionário. RESULTADOS: 19,4% (n=6) dos trabalhadores não usaram todos os equipamentos de proteção individual (EPIs). Foi possível observar diminuição dos parâmetros do eritrograma e alterações na série branca, como leucocitose, neutrofilia e eosinofilia, e no chumbo sérico. Evidenciaram-se valores diminuídos na série vermelha e leucocitose dos trabalhadores que não faziam uso adequado dos EPIs. Quando avaliado o setor de trabalho, pôde-se evidenciar as seguintes associações significativas: fumantes e neutrofilia (p=0,000); setor da moldagem e leucocitose (p=0,023) e eosinofilia (p=0,007); mais de 10 anos de trabalho e leucocitose (p=0,008). CONCLUSÕES: Os dados sugerem que o tempo de trabalho, o tipo de exposição e o uso de EPIs podem alterar exames laboratoriais.
RESUMO
AIM: The aim of this study was to compare the restorative time required and the internal adaptation after thermomechanical aging of class I restorations using either the conventional incremental technique or bulk-fill technique. MATERIALS AND METHODS: Cavities (Class I) were prepared on the occlusal surface of human third molars. 40 teeth were divided into four experimental groups according to the restorative technique (n = 10): G1 = 3 mm increment of Surefill SDR Flow + 1 mm Filtek P60; G2 = 3 mm increment of Filtek Bulk-Fill + 1 mm Filtek P60; G3 = Filtek P60 inserted with incremental technique; G4 = 3 mm increment of Filtek Z350 Flow XT + 1 mm increment of Filtek P60. The required restorative clinical time for each technique was marked. Specimens were submitted to thermomechanical loading (20,000 mechanical cycles-80 N/thermal cycling-5/55°C for 30 seconds). After, samples were sectioned, ratio of internal gaps to interface length (%) was recorded using dye-staining-gap technique. Data were submitted to analysis of variance (ANOVA) and Tukey's test (95% significance). RESULTS: There was no significant difference in gap formation and none of the groups was completely gap-free. However, a significant reduction on required restorative clinical time was observed for G1 (167 ± 7 seconds), G2 (169 ± 4 seconds), and G4 (169 ± 8 seconds) when compared with G3 (204 ± 8 seconds). CONCLUSION: No significant difference in gap formation was found among bulk-fill and conventional incremental restorative technique tested; however, the use of a bulk-fill composite reduced 20% of the required restorative clinical time. CLINICAL SIGNIFICANCE: None of the restorative techniques applied were able to prevent internal gap formation. The use of bulk-fill composite reduced the required clinical time to perform class I restorations.
Assuntos
Resinas Compostas/química , Adaptação Marginal Dentária , Restauração Dentária Permanente , Preparo da Cavidade Dentária , Humanos , Teste de Materiais , Fatores de TempoRESUMO
BACKGROUND: Bauhinia forficata and Cnidoscolus quercifolius plants are commonly used in folk medicine. However, few studies have investigated their therapeutic potential. AIM: Herein, we evaluated the antimicrobial activity of B. forficata and C. quercifolius extracts against microorganisms of clinical relevance and their antiproliferative potential against tumor cells. MATERIALS AND METHODS: The following tests were performed: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC), inhibition of biofilm adhesion, and effects on cell morphology. Antiproliferative tests were carried out with human keratinocytes and six tumor lines. RESULTS: Bauhinia forficata showed antimicrobial activity only against C. albicans with MIC of 15.62 ug/mL and MFC higher than 2000 ug/mL. It also inhibited biofilm adhesion and caused alterations in cell morphology. Cnidoscolus quercifolius showed no significant activity (MIC > 2.0 mg/mL) against the strains. Bauhinia forficata and C. quercifolius extracts showed cytostatic activity against the tumor cells. CONCLUSION: Bauhinia forficata has promising anti-Cand/da activity and should be further investigated for its therapeutic potential. CLINICAL SIGNIFICANCE: The use of medicinal plants in the treatment of infectious processes has an important function nowadays, due to the limitations of the use of synthetic antibiotics available, related specifically to the microbial resistance emergence.
Assuntos
Anti-Infecciosos/farmacologia , Antineoplásicos/farmacologia , Bauhinia , Candida albicans/efeitos dos fármacos , Euphorbiaceae , Medicina Tradicional , Extratos Vegetais/farmacologia , Biofilmes/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Testes de Sensibilidade Microbiana , Folhas de Planta , Plantas MedicinaisRESUMO
AIM: To determine the presence of metallic microfragments and their elemental composition in the dentinal walls of root canals following preparation using different endodontic instruments and to assess the active cutting edges of instruments with regard to structural defects. MATERIALS AND METHODS: A total of 108 molar teeth were selected and prepared using different endodontic instruments. Teeth were randomly divided into nine groups of 12 teeth each, according to the instruments employed: Manual systems -K-FlexoFile, K-File, and Hedstroem; rotary systems - ProTaper Next, Mtwo, BioRaCe; and reciprocating systems - Reciproc, Unicone, and WaveOne. Both root canals and instruments were assessed using scanning electron microscopy, and the elemental composition of metallic microfragments was determined using energy-dispersive X-ray spectroscopy. RESULTS: Metallic microfragments were found in the groups prepared with both manual and reciprocating instruments, with no statistically significant differences between groups, thirds, or presence of metallic microfragments (p ≥ 0.05). Moreover, all groups presented structural defects in both new and used instruments; however, rotary instruments (ProTaper Next, Mtwo 702, BioRaCe) were the ones with the lowest number of defects, at statistically significant differences in comparison with other instruments (p < 0.05). CONCLUSION: The presence of metallic microfragments on dentinal walls following root canal preparation was associated with manual and reciprocating instrumentation. Furthermore, rotary instruments were the ones with the lowest number of defects. Considering the outcomes measured in this study, rotary instruments performed better than the other two groups, as they were associated with the lowest number of metallic microfragments and structural defects. CLINICAL SIGNIFICANCE: During root canal preparation, operative procedures may induce changes to the root canal shape, as well as the release of metallic fragments resulting from the action of instruments on dentinal walls. Therefore, it is important to determine, among the different techniques used for this purpose, which ones are least susceptible to this occurrence.
Assuntos
Dentina/química , Metais/análise , Preparo de Canal Radicular/efeitos adversos , Falha de Equipamento , Humanos , Microscopia Eletrônica de Varredura , Preparo de Canal Radicular/instrumentação , Espectrometria por Raios XRESUMO
ABSTRACT Objective: The objective of this study by the finite element method was to analyze the stress distribution on a single-rooted mandibular premolar tooth restored in two different ways. Methods: Laboratory simulation considered the following situations: 1) premolar restored with gold cast post and ceramic crown; 2) premolar restored with glass fiber post, composite resin core and ceramic crown. For this we used a two-dimensional model of a premolar with load application of 300N in the axial and oblique directions within the ANSYS program for Windows. Results: Under the axial load, a higher concentration of stresses was observed around the cast post (166 MPa). In the oblique load simulation, there was a concentration of stresses on the buccal root wall, internally and externally, in the tooth restored with cast post (222 MPa). In both load directions, the glass fiber post dissipated the stress received with greater uniformity (55 to 111 MPa). Conclusion: These data suggested that from the biomechanical point of view, the use of a glass fiber post and composite resin core could be more advantageous than the cast post technique for a mandibular single-rooted premolar tooth.
RESUMO Objetivo: Analisar, por meio do método dos elementos finitos, a distribuição de tensões em elemento dental pré-molar inferior unirradicular restaurado de duas maneiras distintas. Métodos: A simulação laboratorial considerou as seguintes situações: 1) pré-molar restaurado com núcleo metálico fundido em liga áurea e coroa em cerâmica; 2) pré-molar restaurado com pino de fibra de vidro, núcleo de preenchimento em resina composta e coroa em cerâmica. Para isso foi utilizado um modelo bidimensional de um pré-molar com aplicação de carga de 300N nas direções axial e oblíqua com uso de programa ANSYS para Windows. Resultados: Diante da carga axial, foi observada uma maior concentração de tensões na região do núcleo fundido (166 Mpa). Na simulação de carga oblíqua, observou-se uma concentração de tensões na parede radicular vestibular, interna e externamente, no dente restaurado com núcleo fundido (222 Mpa). Nas duas situações em estudo, o pino de fibra de vidro e núcleo de preenchimento dissipou, com maior uniformidade, a tensão recebida (55 a 111 Mpa). Conclusão: Esses dados sugerem que o uso de pino de fibra pré-fabricado e núcleo de preenchimento em resina composta pode ser mais vantajoso que a indicação de núcleo fundido, sob o ponto-de-vista biomecânico, em dente pré-molar inferior unirradicular.
RESUMO
Several approaches successfully achieve allograft tolerance in preclinical models but are challenging to translate into clinical practice. Many clinically relevant factors can attenuate allograft tolerance induction, including intrinsic genetic resistance, peritransplant infection, inflammation, and preexisting antidonor immunity. The prevailing view for immune memory as a tolerance barrier is that the host harbors memory cells that spontaneously cross-react to donor MHC antigens. Such preexisting "heterologous" memory cells have direct reactivity to donor cells and resist most tolerance regimens. In this study, we developed a model system to determine if an alternative form of immune memory could also block tolerance. We posited that host memory T cells could potentially respond to donor-derived non-MHC antigens, such as latent viral antigens or autoantigens, to which the host is immune. Results show that immunity to a model nonself antigen, ovalbumin (OVA), can dramatically disrupt tolerance despite undetectable initial reactivity to donor MHC antigens. Importantly, this blockade of tolerance was CD8+ T cell-dependent and required linked antigen presentation of alloantigens with the test OVA antigen. As such, this pathway represents an unapparent, or "incognito," form of immunity that is sufficient to prevent tolerance and that can be an unforeseen additional immune barrier to clinical transplant tolerance.
Assuntos
Apresentação de Antígeno/imunologia , Linfócitos T CD8-Positivos/imunologia , Rejeição de Enxerto/imunologia , Memória Imunológica/imunologia , Transplante das Ilhotas Pancreáticas/métodos , Tolerância ao Transplante/imunologia , Animais , Feminino , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Ovalbumina/administração & dosagem , Transplante HomólogoRESUMO
Systemic administration of autologous regulatory dendritic cells (DCreg; unpulsed or pulsed with donor antigen [Ag]), prolongs allograft survival and promotes transplant tolerance in rodents. Here, we demonstrate that nonhuman primate (NHP) monocyte-derived DCreg preloaded with cell membrane vesicles from allogeneic peripheral blood mononuclear cells induce T cell hyporesponsiveness to donor alloantigen (alloAg) in vitro. These donor alloAg-pulsed autologous DCreg (1.4-3.6 × 106 /kg) were administered intravenously, 1 day before MHC-mismatched renal transplantation to rhesus monkeys treated with costimulation blockade (cytotoxic T lymphocyte Ag 4 immunoglobulin [CTLA4] Ig) and tapered rapamycin. Prolongation of graft median survival time from 39.5 days (no DCreg infusion; n = 6 historical controls) and 29 days with control unpulsed DCreg (n = 2), to 56 days with donor Ag-pulsed DCreg (n = 5) was associated with evidence of modulated host CD4+ and CD8+ T cell responses to donor Ag and attenuation of systemic IL-17 production. Circulating anti-donor antibody (Ab) was not detected until CTLA4 Ig withdrawal. One monkey treated with donor Ag-pulsed DCreg rejected its graft in association with progressively elevated anti-donor Ab, 525 days posttransplant (160 days after withdrawal of immunosuppression). These findings indicate a modest but not statistically significant beneficial effect of donor Ag-pulsed autologous DCreg infusion on NHP graft survival when administered with a minimal immunosuppressive drug regimen.
Assuntos
Células Dendríticas/imunologia , Sobrevivência de Enxerto/imunologia , Isoantígenos/imunologia , Falência Renal Crônica/cirurgia , Transplante de Rim , Linfócitos T/imunologia , Doadores de Tecidos , Animais , Leucócitos Mononucleares , Macaca mulatta , Masculino , Tolerância ao Transplante , Transplante HomólogoRESUMO
Because results from single-center (mostly kidney) donor studies demonstrate interpersonal relationship and financial strains for some donors, we conducted a liver donor study involving nine centers within the Adult-to-Adult Living Donor Liver Transplantation Cohort Study 2 (A2ALL-2) consortium. Among other initiatives, A2ALL-2 examined the nature of these outcomes following donation. Using validated measures, donors were prospectively surveyed before donation and at 3, 6, 12, and 24 mo after donation. Repeated-measures regression models were used to examine social relationship and financial outcomes over time and to identify relevant predictors. Of 297 eligible donors, 271 (91%) consented and were interviewed at least once. Relationship changes were positive overall across postdonation time points, with nearly one-third reporting improved donor family and spousal or partner relationships and >50% reporting improved recipient relationships. The majority of donors, however, reported cumulative out-of-pocket medical and nonmedical expenses, which were judged burdensome by 44% of donors. Lower income predicted burdensome donation costs. Those who anticipated financial concerns and who held nonprofessional positions before donation were more likely to experience adverse financial outcomes. These data support the need for initiatives to reduce financial burden.
Assuntos
Transplante de Fígado , Doadores Vivos/psicologia , Fatores Socioeconômicos , Obtenção de Tecidos e Órgãos/economia , Adulto , Feminino , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Apoio Social , Inquéritos e QuestionáriosRESUMO
Regulatory CD4+ Foxp3+ T cells (Tregs) are critical in controlling immunity and tolerance. Thus, preserving Treg numbers and function in transplanted patients is essential for the successful minimization of maintenance immunosuppression. Multiple cellular signals control the development, differentiation, and function of Tregs. Many of these signals are shared with conventional Foxp3- T cells (Tconv) and are targeted by immunosuppressive drugs, negatively affecting both Tregs and Tconv. Because intracellular signals vary in optimal intensity in different T cell subsets, improved specificity in immunosuppressive regimens must occur to benefit long-term transplant outcomes. In this regard, recent advances are gradually uncovering differences in the signals required in Tregs and Tconv biology, opening the door to new potential therapeutic approaches to either enhance or spare Tregs. In this review, we will explain the prominent cell signaling pathways critical for Treg maintenance and function, while reporting the effects of immunosuppressive drugs targeting these signaling pathways in clinical transplantation settings.
Assuntos
Rejeição de Enxerto/imunologia , Imunossupressores/uso terapêutico , Transplante de Rim , Linfócitos T Reguladores/imunologia , Animais , Rejeição de Enxerto/tratamento farmacológico , Humanos , Linfócitos T Reguladores/efeitos dos fármacosRESUMO
Cell damage and death releases alarmins, self-derived immunomodulatory molecules that recruit and activate the immune system. Unfortunately, numerous processes critical to the transplantation of allogeneic materials result in the destruction of donor and recipient cells and may trigger alarmin release. Alarmins, often described as damage-associated molecular patterns, together with exogenous pathogen-associated molecular patterns, are potent orchestrators of immune responses; however, the precise role that alarmins play in alloimmune responses remains relatively undefined. We examined evolving concepts regarding how alarmins affect solid organ and allogeneic hematopoietic cell transplantation outcomes and the mechanisms by which self molecules are released. We describe how, once released, alarmins may act alone or in conjunction with nonself materials to contribute to cytokine networks controlling alloimmune responses and their intensity. It is becoming recognized that this class of molecules has pleotropic functions, and certain alarmins can promote both inflammatory and regulatory responses in transplant models. Emerging evidence indicates that alarmins and their receptors may be promising transplantation biomarkers. Developing the therapeutic ability to support alarmin regulatory mechanisms and the predictive value of alarmin pathway biomarkers for early intervention may provide opportunities to benefit graft recipients.
Assuntos
Alarminas/metabolismo , Doença Enxerto-Hospedeiro/imunologia , Receptores Imunológicos/metabolismo , Animais , Humanos , Transplante HomólogoRESUMO
AIMS: The aim of this study is to evaluate the in vitro response of human gingival fibroblasts in primary cultures to two materials for temporary relining of dentures: Temporary Soft (TDV, Brazil) and Trusoft (Bosworth, USA) for 24 hours, 7 and 30 days by using a multi-parametric analysis. MATERIALS AND METHODS: Each material sample (TDV, TS, Polystyrene, Latex) was prepared and incubated in a culture medium for 1, 7, and 30 days at 37°C. Human gingival fibroblasts were exposed to the extracts and cell viability was evaluated by a multi-parametric assay, which allowed sequential analysis of mitochondrial activity (XTT), membrane integrity [neutral red (NR)], and cell density [crystal violet dye exclusion (CVDE)] in the same cells. Analysis of variance (ANOVA) was used to test the interactions of the three sources of variation (material, test method, and time) with the proportions of viable cells for each relining material. RESULTS: Both evaluated materials (TDV and TS) had low cytotoxic effects during 1, 7, and 30 days after manipulation of the material, as assessed by all three methods used. A statistical difference was found when comparing the negative control group (latex fragments) with the other groups, which showed high toxicity and low percentage of cell viability in all tests used. There was no significant difference among other materials (p > 0.05). CONCLUSION: Low cytotoxicity levels were detected by representatives of the major groups of temporary prosthetic relining materials, as evaluated by multiple cellular viability parameters in human fibroblasts. CLINICAL SIGNIFICANCE: There are various soft materials on the market for relining prostheses; however, the effects of these materials on tissues need to be clarified to avoid problems for patients.
Assuntos
Reembasadores de Dentadura , Fibroblastos/efeitos dos fármacos , Testes de Toxicidade , Brasil , Morte Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Violeta Genciana , Gengiva/citologia , Humanos , Técnicas In Vitro , Teste de Materiais , Vermelho Neutro , Coloração e RotulagemRESUMO
Aim: The aim of this study was to obtain Casearia sylvestris leave extracts by different extractive methods, including the obtention of essential oil, in order to compare their antimicrobial activities to conventional mouthwash chlorhexidine against oral bacteria. Material and method: For this evaluation, extracts from the leaves were obtained by different methods of extraction (infusion, decoction, maceration and percolation) using different solvent systems: water 100%, ethanol 100%, methanol 100%, water: ethanol 3:7; water: ethanol 7:3; water: methanol 7:3 and water: methanol 3:7. The essential oil, which corresponds to a volatile fraction, was obtained by hydrodistillation using Clevenger modified apparatus. The microdilution broth method was used to determine the values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the following microorganisms: Streptococcus mutans ATCC 25175, S. mitis ATCC 49456, S. sanguinis ATCC 10556, S. salivarius ATCC 25975, Lactobacillus casei ATCC 11578 and Enterococcus faecalis ATCC4082. Chlorhexidine gluconate was used as a positive control. Result: All extracts evaluated in the used protocol displayed MIC values higher than 400 µg/mL and few showed bactericidal activity. The antimicrobial activity of essential oil was higher than the activity of the extracts, and the best minimum inhibitory concentration and minimum bactericidal concentration values were obtained against L. casei (MIC of 0.023 µg/mL and MBC of 0.046 µg/mL) and S. mutans (MIC of 25 µg/mL and MBC of 50 µg/mL), respectively. Conclusion: The essential oil of Casearia sylvestris has significant antimicrobial activity against oral microorganisms.
Objetivo: O objetivo deste estudo foi obter extratos por diferentes métodos de extração de Casearia sylvestris, incluindo a obtenção de óleo essencial, a fim de comparar suas atividades antimicrobianas em relação aos enxaguatórios bucais convencionais com clorexidina contra bactérias orais. Material e método: Para esta avaliação, extratos das folhas foram obtidos por diferentes métodos de extração (infusão, decocção, maceração e percolação) utilizando diferentes sistemas de solventes: 100% de água, 100%, de etanol, metanol 100%, água: etanol 3: 7; água: etanol 7: 3; água: metanol 7: 3 e água: metanol 3: 7. O óleo essencial, que corresponde a uma fração volátil, foi obtido por hidrodestilação usando o aparelho de Clevenger modificado. O método de microdiluição em caldo foi usado para determinar os valores de concentração inibitória mínima (MIC) e a concentração bactericida mínima (MBC) para os seguintes microrganismos: Streptococcus mutans ATCC 25175, ATCC 49456 S. mitis, S. sanguinis ATCC 10556, S. salivarius ATCC 25975, Lactobacillus casei ATCC 11578 e Enterococcus faecalis ATCC4082. Gluconato de clorexidina foi usada como um controle positivo. Resultado: Todos os extratos avaliados no protocolo utilizado apresentaram valores de MIC superior a 400 ug/mL e alguns mostraram atividade bactericida. A atividade antimicrobiana do óleo essencial foi maior do que a atividade dos extratos, e a melhor concentração inibitória mínima e valores de concentração bactericida mínima foram obtidos contra L. casei (MIC de 0,023 ug/mL e MBC de 0,046 ug/mL) e S. mutans (MIC de 25 ug/mL e MBC de 50 ug /mL), respectivamente. Conclusão: O óleo essencial de Casearia sylvestris tem atividade antimicrobiana significativa contra microrganismos orais.