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1.
J Fish Biol ; 2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-33112421

RESUMO

A total of 122 Patinga specimens were collected from fish farms (P1, P2 and P3), and only those from fish farm P1 were shown to be infected with Echinorhynchus gomesi. In addition, fish in this study were shown to have diets that consisted of 21 different food items, and Notodiaptomus sp. (Copepoda: Calanoida) was identified as a potential intermediate host for E. gomesi.

2.
Environ Microbiol ; 22(6): 2432-2442, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32329144

RESUMO

Outer membrane vesicles (OMVs) are lipid nanoparticles released by Gram-negative bacteria, which play multiple roles in bacterial physiology and adaptation to diverse environments. In this work, we demonstrate that OMVs released by the environmental pathogen Chromobacterium violaceum deliver the antimicrobial compound violacein to competitor bacteria, mediating its toxicity in vivo at a long distance. OMVs purified by ultracentrifugation from the wild-type strain, but not from a violacein-abrogated mutant ΔvioABCDE, contained violacein and inhibited several Gram-positive bacteria. Competition tests using co-culture and transwell assays indicated that the C. violaceum wild-type strain killed Staphylococcus aureus better than the ΔvioABCDE mutant strain. We found that C. violaceum achieves growth phase-dependent OMV release by the concerted expression of two quorum sensing (QS)-regulated pathways, namely violacein biosynthesis and VacJ/Yrb system. Although both pathways were activated at high cell density in a QS-dependent manner, the effect on vesiculation was the opposite. While the ΔvioABCDE mutant produced twofold fewer vesicles than the wild-type strain, indicating that violacein induces OMV biogenesis for its own delivery, the ΔvacJ and ΔyrbE mutants were hypervesiculating strains. Our findings uncovered QS-regulated pathways involved in OMV biogenesis used by C. violaceum to package violacein into OMVs for interbacterial competition.

3.
Rev. chil. nutr ; 47(1): 105-113, feb. 2020. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1092750

RESUMO

RESUMEN El propósito de este trabajo fue describir las características, motivaciones, barreras y fuentes de información de las mujeres donantes del Banco de Leche en el Complejo Asistencial Dr. Sótero del Río (CASR). Método: El diseño utilizado en este estudio correspondió a uno de tipo transversal descriptivo. Se realizó una encuesta telefónica con 15 preguntas a 82 mujeres que fueron donantes en al menos una oportunidad en el banco de leche del CASR desde el año 2015 a septiembre de 2017. Se estimaron proporciones para las variables categóricas y medidas de tendencia central y de dispersión para la edad Se calcularon intervalos de confianza al 95%. Resultados: La edad media de las donantes fue de 31,3 años con una desviación estándar de 4,6. El 92,7% se encontraba casada o en convivencia y un 58,5% (IC 95% 47,1 - 69,3) cursó educación profesional superior completa. La principal motivación para donar fue la empatia (41,5% [IC 95% 30,7 - 52,9]) y las principales fuentes de conocimiento fueron internet/redes sociales 43,9% (IC 95% 33,0 - 55,3) y personal de salud 32% (IC 95% 22,9 - 44,2). Conclusiones: La mujer donante del banco de leche del CASR, se encuentra principalmente casada o en convivencia, posee un alto nivel educacional y trabaja fuera del hogar. Estos resultados podrían orientar estrategias al fortalecimiento del banco de leche.


ABSTRACT This study sought to describe characteristics, motivations, barriers, and sources of information of human milk donors to the milk bank at Dr. Sótero del Río Hospital, Chile. Methods: A descriptive and cross - sectional study was carried out. We conducted a 15-question telephone survey in 82 women who were at least one-time milk donors between 2015 and 2017. Statistical analysis included frequencies and percentages for categorical variables and measures of central tendency and dispersion for quantitative variables. We calculated 95% confidence intervals (CI). Results: The mean age of donors was 31.34,6 years; 92.7% were married or were living with their partner and 58.5% (95% CI of 47.1- 69.3) had completed higher education. The main motivation for donating was helping others (41.5% [95% CI of 30.7- 52.9]). The primary sources of knowledge on milk donations were the internet and social networks (43.9% [IC 95% 33.0- 55.3]), followed by health personnel 32% (95% CI of 22.9- 44.2). Conclusions: The donor profile in CASR's milk bank is a young woman, with a stable partner and high educational level. These results could provide useful information to improve strategies for human milk donation.

4.
Dent Mater ; 36(2): e29-e37, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31831181

RESUMO

OBJECTIVE: The aim of this study was to evaluate the effect of different photoinitiator systems on the cell viability and physico-chemical properties of an experimental adhesive resin of a two-step self-etch adhesive system. METHODS: Eight photoinitiators and coinitiators were evaluated, camphorquinone (CQ); ethyl-dimethylamino benzoate (EDAB); diphenyliodonium hexafluorophosphate (DPIHFP); 1,3-benzodioxole (BDO); piperonyl alcohol (AP); 1,3-diethyl-2-thiobarbituric acid (TBA); bisphenyl phosphinic oxide (BAPO); and diphenyl phosphinic oxide (TPO). Seven experimental adhesive resins (Bis-GMA:TEGDMA - 1:1 by wt%) were formulated by varying the initiation systems: RCQ+EDAB (control), RCQ+EDAB+DPHFP, RCQ+BDO, RCQ+AP, RCQ+TBA, RBAPO and RTPO. The cell viability of the different photoinitiators in their isolated form and after being incorporated into the adhesive resins was evaluated using the MTT assay. The degree of conversion within the hybrid layer (DC in situ) was evaluated by micro-Raman spectroscopy; the polymerization kinetics, by FTIR spectroscopy. The water sorption (Wsp) and solubility (Wsl) were calculated by using percentage of gain and loss of mass. Data were analyzed using One-way ANOVA and Kruskal-Wallis tests (α=0.05). RESULTS: When evaluated in their isolated form, the DPIHFP was considered cytotoxic in all concentrations evaluated. When incorporated into and adhesive resin, RCQ+TBA presented higher cell viability values than control and the highest values of DC in situ (p<0.05). Additionally, the use of CQ+TBA showed a higher cell viability when compared with the conventional CQ+EDAB system. SIGNIFICANCE: The pair CQ+TBA could be potentially useful in the development of materials with improved biocompatibility.


Assuntos
Resinas Compostas , Cimentos Dentários , Bis-Fenol A-Glicidil Metacrilato , Teste de Materiais , Polimerização , Solubilidade
5.
Plants (Basel) ; 8(12)2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31795413

RESUMO

Ginkgo biloba L. leaf extracts and herbal infusions are used worldwide due to the health benefits that are attributed to its use, including anti-neoplastic, anti-aging, neuro-protection, antioxidant and others. The aim of this study was to evaluate the effect of an aqueous Ginkgo biloba extract on HepG2 cell viability, genotoxicity and DNA protection against paraquat-induced oxidative damage. Exposure to paraquat (PQ), over 24 h incubation at 1.0 and 1.5 µM, did not significantly reduce cell viability but induced concentration and time-dependent oxidative DNA damage. Ginkgo biloba leaf extract produced dose-dependent cytotoxicity (IC50 = 540.8 ± 40.5 µg/mL at 24 h exposure), and short incubations (1 h) produced basal and oxidative DNA damage (>750 and 1500 µg/mL, respectively). However, lower concentrations (e.g., 75 µg/mL) of Ginkgo biloba leaf extract were not cytotoxic and reduced basal DNA damage, indicating a protective effect at incubations up to 4 h. On the other hand, longer incubations (24 h) induced oxidative DNA damage. Co-incubation of HepG2 cells for 4 h, with G. biloba leaf extract (75 µg/mL) and PQ (1.0 or 1.5 µM) significantly reduced PQ-induced oxidative DNA damage. In conclusion, the consumption of Ginkgo biloba leaf extract for long periods at high doses/concentrations is potentially toxic; however, low doses protect the cells against basal oxidative damage and against environmentally derived toxicants that induce oxidative DNA damage.

6.
Clin Oral Investig ; 23(3): 1143-1151, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29961139

RESUMO

OBJECTIVE: The aim of this study was to evaluate the degree of conversion, ultimate tensile strength, cell viability, and oxidative stress of two different ternary initiation systems, using two photoinitiation polymerization times. METHODS: The groups investigated were camphorquinone (CQ); CQ and diphenyleneiodonium hexafluorophosphate (DPI); CQ and ethyl 4-dimethylamine benzoate (EDAB); and CQ, EDAB, and DPI, with EDAB in high and low concentration. To assess the degree of conversion (DC) and the ultimate tensile strength (UTS), a real-time Fourier transform infrared spectroscopy and a universal test machine Emic DL-500 were used, respectively. Cell viability and oxidative stress were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), superoxide dismutase (SOD), total sulfhydryl (SH) content, and thiobarbituric acid reactive species (TBARS) formation assays. RESULTS: Slight lower cell viability was shown when DPI was associated with high concentrations of EDAB; this reduction seemed to be attenuated when lower concentrations of EDAB were used. When EDAB and DPI were associated, no oxidative damage was shown. The degree of conversion was increased in the ternary systems (CQ + EDAB lower concentration + DPI) group, which did not affect the UTS, cytotoxicity, and oxidative stress parameters. The polymerization time did not affect cell viability, total SH, and TBARS; however, a slight increase was shown in SOD levels. CLINICAL RELEVANCE: Our study emphasizes the relevance of incorporating the third element-iodonium salt-in a binary adhesive systems composed exclusively of CQ and EDAB.


Assuntos
Cimentos Dentários , Estresse Oxidativo , Sobrevivência Celular , Teste de Materiais , Metacrilatos , Polimerização , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração
7.
Braz Oral Res ; 32: e104, 2018 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-30328894

RESUMO

This study evaluated the three-year lifespan of the bond to dentin of experimental self-etch adhesives containing benzodioxole derivatives - 1,3-benzodioxole (BDO) and piperonyl alcohol (PA) - as co-initiator alternative to amines. Adhesive resins were formulated using Bis-GMA, TEGDMA, HEMA, camphorquinone and different co-initiators: BDO, PA or ethyl 4-dimethylamino benzoate (EDAB - amine). An experimental self-etch primer was used to complete the two-step, self-etch adhesive system. Clearfil SE Bond (CSE) was used as commercial reference. Bond strength to human dentin was assessed by microtensile bond strength (µTBS) test, and failure mode was classified. Morphology of the dentin bonding interface was assessed via scanning electron microscopy (SEM). Irrespective of the dental adhesives evaluated, µTBS was higher after 24 hours compared with that after 1.5 and 3 years (p ≤ 0.001). However, adhesives with BDO and PA as co-initiators showed significantly higher bond strength than the bonding resin with EDAB (p ≤ 0.002), independent of the time evaluated. The commercial adhesive CSE showed similar bond strength compared with the other groups (p ≥ 0.05). Mixed failures were mainly observed after 24 hours, while adhesive failures were more frequently observed after 1.5 and 3 years. No notable differences in homogeneity and continuity along the bonded interfaces were detected among the materials in the SEM analysis. In conclusion, benzodioxole derivatives are feasible alternative co-initiators to tertiary amine in camphorquinone-based self-etching dental adhesive formulations.


Assuntos
Benzodioxóis/química , Álcoois Benzílicos/química , Adesivos Dentinários/química , Dentina/efeitos dos fármacos , Dioxóis/química , Cimentos de Resina/química , para-Aminobenzoatos/química , Bis-Fenol A-Glicidil Metacrilato/química , Cânfora/análogos & derivados , Cânfora/química , Colagem Dentária/métodos , Dentina/química , Humanos , Teste de Materiais , Metacrilatos/química , Microscopia Eletrônica de Varredura , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Reprodutibilidade dos Testes , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo
8.
Virulence ; 9(1): 1230-1246, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30027802

RESUMO

Mycoplasma hyopneumoniae and Mycoplasma flocculare are genetically similar bacteria, which coinhabit the porcine respiratory tract. These mycoplasmas share most of the known virulence factors, but, while M. hyopneumoniae causes porcine enzootic pneumonia (PEP), M. flocculare is a commensal species. To identify potential PEP determinants and provide novel insights on mycoplasma-host interactions, the whole cell proteomes of two M. hyopneumoniae strains, one pathogenic (7448) and other non-pathogenic (J), and M. flocculare were compared. A cell fractioning approach combined with mass spectrometry (LC-MS/MS) proteomics was used to analyze cytoplasmic and surface-enriched protein fractions. Average detection of ~ 50% of the predicted proteomes of M. hyopneumoniae 7448 and J, and M. flocculare was achieved. Many of the identified proteins were differentially represented in M. hyopneumoniae 7448 in comparison to M. hyopneumoniae J and M. flocculare, including potential PEP determinants, such as adhesins, proteases, and redox-balancing proteins, among others. The LC-MS/MS data also provided experimental validation for several genes previously regarded as hypothetical for all analyzed mycoplasmas, including some coding for proteins bearing virulence-related functional domains. The comprehensive proteome profiling of two M. hyopneumoniae strains and M. flocculare provided tens of novel candidates to PEP determinants or virulence factors, beyond those classically described.


Assuntos
Interações entre Hospedeiro e Microrganismos , Mycoplasma hyopneumoniae/metabolismo , Mycoplasma/metabolismo , Pneumonia Suína Micoplasmática/microbiologia , Proteoma/metabolismo , Adesinas Bacterianas/análise , Animais , Proteínas de Bactérias/análise , Espectrometria de Massas , Mycoplasma hyopneumoniae/patogenicidade , Peptídeo Hidrolases/análise , Especificidade da Espécie , Suínos , Fatores de Virulência
9.
Protoplasma ; 255(6): 1725-1740, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29789939

RESUMO

Grapevine varieties respond differentially to heat stress (HS). HS ultimately reduces the photosynthesis and respiratory performance. However, the HS effects in the leaf nuclei and mitotic cells of grapevine are barely known. This work intends to evaluate the HS effects in the leaf mitotic cell cycle and chromosomes of four wine-producing varieties: Touriga Franca (TF), Touriga Nacional (TN), Rabigato, and Viosinho. In vitro plants with 11 months were used in a stepwise acclimation and recovery (SAR) experimental setup comprising different phases: heat acclimation period (3 h-32 °C), extreme HS (1 h-42 °C), and two recovery periods (3 h-32 °C and 24 h-25 °C), and compared to control plants (maintained in vitro at 25 °C). At the end of each SAR phase, leaves were collected, fixed, and used for cell suspensions and chromosome preparations. Normal and abnormal interphase and mitotic cells were observed, scored, and statistically analyzed in all varieties and treatments (control and SAR phases). Different types of chromosomal anomalies in all mitotic phases, treatments, and varieties were found. In all varieties, the percentage of dividing cells with anomalies (%DCA) after extreme HS increased relative to control. TF and Viosinho were considered the most tolerant to HS. TF showed a gradual MI reduction from heat acclimation to HS and the lowest %DCA after HS and 24 h of recovery. Only Viosinho reached the control values after the long recovery period. Extrapolating these data to the field, we hypothesize that during consecutive hot summer days, the grapevine plants will not have time or capacity to recover from the mitotic anomalies caused by high temperatures.


Assuntos
Cromossomos de Plantas/metabolismo , Resposta ao Choque Térmico/fisiologia , Mitose , Folhas de Planta/citologia , Vitis/citologia , Vinho , Interfase , Índice Mitótico
10.
Braz Oral Res ; 32: e15, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29513888

RESUMO

This study evaluated the shear bond strength (SBS) of self-adhesive resin cements (SARCs) to dentin and their physical-chemical properties. Five commercial SARCs were evaluated [SmartCem®2 - DENTSPLY (SC2); BisCem® - Bisco (BC); SeT PP® - SDI (SeT); Relyx U100® - 3M ESPE (U100) and YCEM® SA - Yller (YCEM)]. The SARCs were evaluated for SBS to dentin (n = 10) after 24 h, 6 months, and 12 months. The dentin demineralization caused by acidic monomers was observed by SEM, and pH-neutralization of eluate was observed for 24 h. Degree of conversion (DC), rate of polymerization (Rp), flexural strength (FS), and elastic modulus (E) were evaluated. Immediate SBS of SC2, SET, U100, and YCEM were statistically higher than that of BC (p < 0.001). After 12 months, all SARCs showed reduced SBS values and U100 showed values similar to those of SET and YCEM, and higher than those of BC and SC2 (p = 0.001). Demineralization pattern of SARCs was similar. At 24h, all SARCs showed no differences in the pH-value, except BC and U100 (p < 0.001). YCEM showed the highest Rp. U100, YCEM, and SC2 showed statistically higher FS (p<0.001) and E (p < 0.001) when compared with SET and BC. U100 and YCEM showed the best long-term bonding irrespective of the storage period. A significant reduction in SBS was found for all groups after 12 months. SBS was not shown to be correlated with physical-chemical properties, and appeared to be material-dependent. The polymerization profile suggested that an increased time of light activation, longer than that recommended by manufacturers, would be necessary to optimize DC of SARCs.


Assuntos
Resinas Compostas/química , Dentina/efeitos dos fármacos , Cura Luminosa de Adesivos Dentários/métodos , Cimentos de Resina/química , Análise de Variância , Dentina/química , Módulo de Elasticidade , Teste de Materiais , Microscopia Eletrônica de Varredura , Transição de Fase/efeitos dos fármacos , Maleabilidade , Polimerização , Valores de Referência , Reprodutibilidade dos Testes , Resistência ao Cisalhamento , Propriedades de Superfície/efeitos dos fármacos , Fatores de Tempo
11.
Braz. oral res. (Online) ; 32: e15, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-889485

RESUMO

Abstract This study evaluated the shear bond strength (SBS) of self-adhesive resin cements (SARCs) to dentin and their physical-chemical properties. Five commercial SARCs were evaluated [SmartCem®2 - DENTSPLY (SC2); BisCem® - Bisco (BC); SeT PP® − SDI (SeT); Relyx U100® - 3M ESPE (U100) and YCEM® SA - Yller (YCEM)]. The SARCs were evaluated for SBS to dentin (n = 10) after 24 h, 6 months, and 12 months. The dentin demineralization caused by acidic monomers was observed by SEM, and pH-neutralization of eluate was observed for 24 h. Degree of conversion (DC), rate of polymerization (Rp), flexural strength (FS), and elastic modulus (E) were evaluated. Immediate SBS of SC2, SET, U100, and YCEM were statistically higher than that of BC (p < 0.001). After 12 months, all SARCs showed reduced SBS values and U100 showed values similar to those of SET and YCEM, and higher than those of BC and SC2 (p = 0.001). Demineralization pattern of SARCs was similar. At 24h, all SARCs showed no differences in the pH-value, except BC and U100 (p < 0.001). YCEM showed the highest Rp. U100, YCEM, and SC2 showed statistically higher FS (p<0.001) and E (p < 0.001) when compared with SET and BC. U100 and YCEM showed the best long-term bonding irrespective of the storage period. A significant reduction in SBS was found for all groups after 12 months. SBS was not shown to be correlated with physical-chemical properties, and appeared to be material-dependent. The polymerization profile suggested that an increased time of light activation, longer than that recommended by manufacturers, would be necessary to optimize DC of SARCs.


Assuntos
Resinas Compostas/química , Cimentos de Resina/química , Dentina/efeitos dos fármacos , Cura Luminosa de Adesivos Dentários/métodos , Valores de Referência , Propriedades de Superfície/efeitos dos fármacos , Fatores de Tempo , Teste de Materiais , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Análise de Variância , Maleabilidade , Resistência ao Cisalhamento , Dentina/química , Transição de Fase/efeitos dos fármacos , Módulo de Elasticidade , Polimerização
12.
Braz. oral res. (Online) ; 32: e104, 2018. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-974458

RESUMO

Abstract This study evaluated the three-year lifespan of the bond to dentin of experimental self-etch adhesives containing benzodioxole derivatives - 1,3-benzodioxole (BDO) and piperonyl alcohol (PA) - as co-initiator alternative to amines. Adhesive resins were formulated using Bis-GMA, TEGDMA, HEMA, camphorquinone and different co-initiators: BDO, PA or ethyl 4-dimethylamino benzoate (EDAB - amine). An experimental self-etch primer was used to complete the two-step, self-etch adhesive system. Clearfil SE Bond (CSE) was used as commercial reference. Bond strength to human dentin was assessed by microtensile bond strength (µTBS) test, and failure mode was classified. Morphology of the dentin bonding interface was assessed via scanning electron microscopy (SEM). Irrespective of the dental adhesives evaluated, µTBS was higher after 24 hours compared with that after 1.5 and 3 years (p ≤ 0.001). However, adhesives with BDO and PA as co-initiators showed significantly higher bond strength than the bonding resin with EDAB (p ≤ 0.002), independent of the time evaluated. The commercial adhesive CSE showed similar bond strength compared with the other groups (p ≥ 0.05). Mixed failures were mainly observed after 24 hours, while adhesive failures were more frequently observed after 1.5 and 3 years. No notable differences in homogeneity and continuity along the bonded interfaces were detected among the materials in the SEM analysis. In conclusion, benzodioxole derivatives are feasible alternative co-initiators to tertiary amine in camphorquinone-based self-etching dental adhesive formulations.

13.
Cad. CEDES ; 37(103): 335-346, set.-dez. 2017. tab
Artigo em Português | LILACS-Express | LILACS | ID: biblio-889587

RESUMO

RESUMO: A realidade educacional das crianças pequenas que residem em área rural do país, com idade para frequentar a educação infantil, mostra-se um desafio à política de educação brasileira. A produção de conhecimento recente aponta que o acesso delas à educação infantil é desigual e insuficiente quando comparado ao acesso que crianças da mesma faixa etária e residentes em área urbana têm a essa etapa da educação básica. O artigo lança luz sobre a oferta de educação infantil no estado da Paraíba, com ênfase no contexto rural.


ABSTRACT: The educational reality of young children living in rural areas of Brazil, who are old enough to attend early childhood education, is a challenge to Brazilian education policy. Recent knowledge production indicates that their access to early childhood education is unequal and insufficient when compared to the access that children of the same age group and who live in urban areas have to this stage of basic education. The article throws light on the offer of early childhood education in the state of Paraíba, Brazil, with emphasis on the rural context.

14.
Braz. dent. j ; 28(3): 354-361, May-June 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-888645

RESUMO

Abstract This study investigated the in vitro performance of the commercial bis-acryl composite resins Systemp C&B II (SYS, Ivoclar Vivadent), Protemp 4 (PT4, 3M ESPE), Structur 2C (ST2, Voco) and ProviPlast (PVP, Biodinamica). Characterization involved optical (color stability, translucency parameter, fluorescence), surface (roughness, morphology and elemental composition), physical-chemical (viscosity, polymerization kinetics) and mechanical analyses (Poisson ratio, biaxial flexural strength, flexural modulus). Most tests were carried out after 24 h, but optical and mechanical analyses were carried out after storage in water at 37 °C for 1, 15, and 30 days. Data were statistically analyzed (a=0.05). Most results were material dependent. SYS and PT4 showed stability in color and translucency over time. All materials had similar or higher fluorescence than human enamel. SC2 and PVP showed rougher surfaces than the other bis-acryl composites. Smaller filler particles were observed on the surface of PT4 and PVP compared with the coarser particles from ST2 and SYS. Viscosity readings indicated a thixotropic behavior for all tested materials. SYS had the lowest and PT4 the highest degree of C=C conversion after 10 min. In the polymerization kinetics, PT4 had the highest maximum polymerization rate and reached earlier the transition between polymerization autoacceleration and autodeceleration. PT4 and SYS had significantly higher flexural strength and modulus than ST2 and PVP for most storage times. Results for Poisson ratio varied between materials. Longer storage periods were generally associated with higher frequency of catastrophic failures in the flexural tests. In conclusion, the performance of bis-acryl composite resins varied largely among materials.


Resumo Este estudo investigou o desempenho in vitro de quatro resinas compostas bisacrílicas comerciais: Systemp C&B II (SYS, Ivoclar Vivadent), Protemp 4 (PT4, 3M ESPE), Structur 2C (ST2, Voco) e ProviPlast (PVP, Biodinamica). A caracterização envolveu análises ópticas (estabilidade de cor, parâmetro de translucidez, fluorescência), de superfície (rugosidade, morfologia e composição elementar), físico-químicas (viscosidade, cinética de polimerização) e mecânicas (razão de Poisson, resistência à flexão biaxial, módulo de elasticidade). A maioria dos testes foram realizados após 24 h, enquanto análises ópticas e mecânicas foram realizadas após armazenamento em água a 37 °C por 1, 15 e 30 dias. Os dados foram analisados estatisticamente (a=0,05). Grande parte dos resultados foi dependente do material. SYS e PT4 mostraram estabilidade de cor e translucidez ao longo do tempo. Todos os materiais apresentaram fluorescência similar ou maior que o esmalte humano. SC2 e PVP apresentaram superfícies mais rugosas que os outros materiais. Menores partículas de carga foram observadas na superfície de PT4 e PVP comparadas às partículas mais irregulares de ST2 e SYS. As leituras de viscosidade indicaram comportamento tixotrópico para todos os materiais testados. SYS teve a menor e PT4 o maior grau de conversão de C=C após 10 min. Na cinética de polimerização, PT4 teve a maior taxa máxima de polimerização e atingiu mais cedo a transição entre autoaceleração e autodesaceleração da polimerização. PT4 e SYS apresentaram resistência à flexão e módulo de elasticidade significativamente maiores que ST2 e PVP na maioria dos períodos de armazenamento. Resultados da razão de Poisson variaram entre os materiais. Períodos mais longos de armazenamento foram em geral associados a maior frequência de falhas catastróficas nos testes de flexão. Em conclusão, o desempenho das resinas compostas bisacrílicas variou amplamente entre os materiais.


Assuntos
Humanos , Resinas Compostas , Restauração Dentária Temporária , Esmalte Dentário/química , Análise do Estresse Dentário , Fluorescência , Cinética , Microscopia Eletrônica de Varredura , Distribuição de Poisson , Polimerização , Propriedades de Superfície , Viscosidade
15.
Restor Dent Endod ; 42(2): 105-110, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28503475

RESUMO

OBJECTIVES: This study investigated the cleaning ability of ultrasonically activated irrigation (UAI) and a novel activation system with reciprocating motion (EC, EasyClean, Easy Equipamentos Odontológicos) when used with a relatively new chelating agent (QMix, Dentsply). In addition, the effect of QMix solution when used for a shorter (1 minute) and a longer application time (3 minutes) was investigated. MATERIALS AND METHODS: Fifty permanent human teeth were prepared with K3 rotary system and 6% sodium hypochlorite. Samples were randomly assigned to five groups (n = 10) according to the final irrigation protocol: G1, negative control (distilled water); G2, positive control (QMix 1 minute); G3, QMix 1 minute/UAI; G4, QMix 1 minute/EC; G5, QMix 3 minutes. Subsequently the teeth were prepared and three photomicrographs were obtained in each root third of root walls, by scanning electron microscopy. Two blinded and pre-calibrated examiners evaluated the images using a four-category scoring system. Data were statistically analyzed using Kruskal-Wallis and Dunn tests (p < 0.05). RESULTS: There were differences among groups (p < 0.05). UAI showed better cleaning ability than EC (p < 0.05). There were improvements when QMix was used with auxiliary devices in comparison with conventional irrigation (p < 0.05). Conventional irrigation for 3 minutes presented significantly better results than its use for 1 minute (p < 0.05). CONCLUSIONS: QMix should be used for 1 minute when it is used with UAI, since this final irrigation protocol showed the best performance and also allowed clinical optimization of this procedure.

16.
Vet Microbiol ; 201: 170-176, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28284605

RESUMO

Mycoplasma hyopneumoniae is an economically significant swine pathogen that causes porcine enzootic pneumonia (PEP). Important processes for swine infection by M. hyopneumoniae depend on cell surface proteins, many of which are secreted by secretion pathways not completely elucidated so far. A putative type I signal peptidase (SPase I), a possible component of a putative Sec-dependent pathway, was annotated as a product of the sipS gene in the pathogenic M. hyopneumoniae 7448 genome. This M. hyopneumoniae putative SPase I (MhSPase I) displays only 14% and 23% of sequence identity/similarity to Escherichia coli bona fide SPase I, and, in complementation assays performed with a conditional E. coli SPase I mutant, only a partial restoration of growth was achieved with the heterologous expression of a recombinant MhSPase I (rMhSPase I). Considering the putative surface location of MhSPase I and its previously demonstrated capacity to induce a strong humoral response, we then assessed its potential to elicit a cellular and possible immunomodulatory response. In assays for immunogenicity assessment, rMhSPase I unexpectedly showed a cytotoxic effect on murine splenocytes. This cytotoxic effect was further confirmed using the swine epithelial PK(15) cell line in MTT and annexin V-flow cytometry assays, which showed that rMhSPase I induces apoptosis in a dose dependent-way. It was also demonstrated that this pro-apoptotic effect of rMhSPase I involves activation of a caspase-3 cascade. The potential relevance of the rMhSPase I pro-apoptotic effect for M. hyopneumoniae-host interactions in the context of PEP is discussed.


Assuntos
Apoptose , Proteínas de Membrana/metabolismo , Mycoplasma hyopneumoniae/enzimologia , Pneumonia Suína Micoplasmática/microbiologia , Serina Endopeptidases/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular , Proteínas de Membrana/genética , Mycoplasma hyopneumoniae/genética , Serina Endopeptidases/genética , Suínos , Fatores de Virulência
17.
Heliyon ; 3(1): e00225, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28194450

RESUMO

The adjuvant potential of two mesoporous silica nanoparticles (MSNs), SBa-15 and SBa-16, was assessed in combination with a recombinant HSP70 surface polypeptide domain from Mycoplasma hyopneumoniae, the etiological agent of porcine enzootic pneumonia (PEP). The recombinant antigen (HSP70212-600), previously shown as immunogenic in formulation with classic adjuvants, was used to immunize BALB/c mice in combination with SBa-15 or SBa-16 MSNs, and the effects obtained with these formulations were compared to those obtained with alum, the adjuvant traditionally used in anti-PEP bacterins. The HSP70212-600 + SBa-15 vaccine elicited a strong humoral immune response, with high serum total IgG levels, comparable to those obtained using HSP70212-600 + alum. The HSP70212-600 + SBa-16 vaccine elicited a moderate humoral immune response, with lower levels of total IgG. The cellular immune response was assessed by the detection of IFN-γ, IL-4 and IL-10 in splenocyte culture supernatants. The HSP70212-600 + SBa-15 vaccine increased IFN-γ, IL-4 and IL-10 levels, while no stimulation was detected with the HSP70212-600 + SBa-16 vaccine. The HSP70212-600 + SBa-15 vaccine induced a mixed Th1/Th2-type response, with an additional IL-10 mediated anti-inflammatory effect, both of relevance for an anti-PEP vaccine. Alum adjuvant controls stimulated an unspecific cellular immune response, with similar levels of cytokines detected in mice immunized either with HSP70212-600 + alum or with the adjuvant alone. The better humoral and cellular immune responses elicited in mice indicated that SBa-15 has adjuvant potential, and can be considered as an alternative to the use of alum in veterinary vaccines. The use of SBa-15 with HSP70212-600 is also promising as a potential anti-PEP subunit vaccine formulation.

18.
Braz Dent J ; 28(3): 354-361, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29297557

RESUMO

This study investigated the in vitro performance of the commercial bis-acryl composite resins Systemp C&B II (SYS, Ivoclar Vivadent), Protemp 4 (PT4, 3M ESPE), Structur 2C (ST2, Voco) and ProviPlast (PVP, Biodinamica). Characterization involved optical (color stability, translucency parameter, fluorescence), surface (roughness, morphology and elemental composition), physical-chemical (viscosity, polymerization kinetics) and mechanical analyses (Poisson ratio, biaxial flexural strength, flexural modulus). Most tests were carried out after 24 h, but optical and mechanical analyses were carried out after storage in water at 37 °C for 1, 15, and 30 days. Data were statistically analyzed (a=0.05). Most results were material dependent. SYS and PT4 showed stability in color and translucency over time. All materials had similar or higher fluorescence than human enamel. SC2 and PVP showed rougher surfaces than the other bis-acryl composites. Smaller filler particles were observed on the surface of PT4 and PVP compared with the coarser particles from ST2 and SYS. Viscosity readings indicated a thixotropic behavior for all tested materials. SYS had the lowest and PT4 the highest degree of C=C conversion after 10 min. In the polymerization kinetics, PT4 had the highest maximum polymerization rate and reached earlier the transition between polymerization autoacceleration and autodeceleration. PT4 and SYS had significantly higher flexural strength and modulus than ST2 and PVP for most storage times. Results for Poisson ratio varied between materials. Longer storage periods were generally associated with higher frequency of catastrophic failures in the flexural tests. In conclusion, the performance of bis-acryl composite resins varied largely among materials.


Assuntos
Resinas Compostas , Restauração Dentária Temporária , Esmalte Dentário/química , Análise do Estresse Dentário , Fluorescência , Humanos , Cinética , Microscopia Eletrônica de Varredura , Distribuição de Poisson , Polimerização , Propriedades de Superfície , Viscosidade
19.
J Oral Sci ; 58(4): 561-567, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28025441

RESUMO

This study evaluated the effects of different auxiliary irrigation devices on smear layer removal with a chelating solution (QMix). Fifty single-rooted permanent human teeth were shaped with a sequence of nickel-titanium instruments. A 2% chlorhexidine gel was used as a chemical auxiliary substance during preparation. Samples were assigned to five groups (n = 10 each) according to final irrigation protocol, namely, distilled water (control group), QMix 1 min, QMix + passive ultrasonic irrigation (PUI), QMix + plastic endodontic finishing file (EC), and QMix 3 min. Teeth were prepared and evaluated by scanning electron microscopy, and three photomicrographs (magnification, 1,000×) were obtained for each root third. Two blinded and precalibrated evaluators analyzed and scored the images, and the data were statistically analyzed by the Kruskal-Wallis and Dunn tests (P < 0.05). Groups were ranked according to the extent of smear layer removal. The total area of the root canal walls and apical root thirds was calculated, and the groups ranked PUI > EC = QMix 3 min > QMix 1 min > control. QMix 1 min was effective for smear layer removal only when used with auxiliary devices, and QMix + passive ultrasonic irrigation yielded the best results, particularly for the apical third.(J Oral Sci 58, 561-567, 2016).


Assuntos
Irrigantes do Canal Radicular , Camada de Esfregaço , Estudos de Casos e Controles , Humanos , Microscopia Eletrônica de Varredura
20.
Vet Microbiol ; 190: 50-57, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27283856

RESUMO

Mycoplasma hyopneumoniae and Mycoplasma flocculare are two genetically close species found in the swine respiratory tract. Despite their similarities, while M. hyopneumoniae is the causative agent of porcine enzootic pneumonia, M. flocculare is a commensal bacterium. Genomic and transcriptional comparative analyses so far failed to explain the difference in pathogenicity between these two species. We then hypothesized that such difference might be, at least in part, explained by amino acid sequence and immunological or functional differences between ortholog surface proteins. In line with that, it was verified that approximately 85% of the ortholog surface proteins from M. hyopneumoniae 7448 and M. flocculare present one or more differential domains. To experimentally assess possible immunological implications of this kind of difference, the extracellular differential domains from one pair of orthologous surface proteins (MHP7448_0612, from M. hyopneumoniae, and MF_00357, from M. flocculare) were expressed in E. coli and used to immunize mice. The recombinant polypeptides (rMHP61267-169 and rMF35767-196, respectively) induced distinct cellular immune responses. While, rMHP61267-169 induced both Th1 and Th2 responses, rMF35767-196 induced just an early pro-inflammatory response. These results indicate that immunological properties determined by differential domains in orthologous surface protein might play a role in pathogenicity, contributing to elicit specific and differential immune responses against each species.


Assuntos
Imunidade Celular/imunologia , Proteínas de Membrana/imunologia , Mycoplasma hyopneumoniae/imunologia , Mycoplasma/imunologia , Domínios Proteicos/imunologia , Animais , Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Camundongos , Proteínas Recombinantes/imunologia , Especificidade da Espécie
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