Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Caries Res ; 51(2): 141-148, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28125809

RESUMEN

Although several studies have demonstrated the efficacy of AmF/NaF/SnCl2 solution in inhibiting dental erosion progression, measures for further improvement in its effectiveness are paramount. Thus, this in situ study evaluated whether the protective effect promoted by the AmF/NaF/SnCl2 solution would be enhanced by increasing its frequency of use. The study was conducted with 12 volunteers, a 4-phase (5 days each) randomized, crossover model. Extraoral erosive challenges (0.5% citric acid, pH 2.6, 6 × 2 min/day) and rinsing protocol (1 or 2 × 2 min/day) were performed. Before the in situ phase, human enamel samples were subjected to an in vitro surface softening (1% citric acid, pH 4.0, for 3 min). Four treatment protocols were tested using samples in replicas (n = 12): group G1 - deionized water (negative control); G2 - NaF solution (positive control, 500 ppm F-, pH 4.5); G3 - AmF/NaF/SnCl2 solution (500 ppm F-, 800 ppm Sn2+, pH 4.5) once a day; G4 - AmF/NaF/SnCl2 solution twice a day. Tissue loss and morphological changes were determined by optical profilometry (n = 12) and scanning electron microscopy (n = 3) analysis, respectively. Data were statistically analyzed by ANOVA with subsequent pairwise comparison of treatments. Tissue loss means (±SD in µm) for each treatment protocol and statistical differences were found as follows: G1 4.55 ± 2.75, G2 4.59 ± 2.13, G3 2.64 ± 1.55, and G4 1.34 ± 1.16. Although there was no difference between the 2 AmF/NaF/SnCl2 solution application regimens (once or twice a day), application of the product twice a day was the only treatment that was able to control erosion progression, differing from the control groups.


Asunto(s)
Fluoruros Tópicos/administración & dosificación , Antisépticos Bucales/administración & dosificación , Fluoruro de Sodio/administración & dosificación , Compuestos de Estaño/administración & dosificación , Erosión de los Dientes/prevención & control , Adulto , Estudios Cruzados , Progresión de la Enfermedad , Método Doble Ciego , Humanos , Estudios Prospectivos
2.
J Biomed Biotechnol ; 2010: 376218, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20300433

RESUMEN

Stannous chloride (SnCl(2)) and UVA induce DNA lesions through ROS. The aim of this work was to study the toxicity induced by UVA preillumination, followed by SnCl(2) treatment. E. coli BER mutants were used to identify genes which could play a role in DNA lesion repair generated by these agents. The survival assays showed (i) The nfo mutant was the most sensitive to SnCl(2); (ii) lethal synergistic effect was observed after UVA pre-illumination, plus SnCl(2) incubation, the nfo mutant being the most sensitive; (iii) wild type and nfo mutants, transformed with pBW21 plasmid (nfo(+)) had their survival increased following treatments. The alkaline agarose gel electrophoresis assays pointed that (i) UVA induced DNA breaks and fpg mutant was the most sensitive; (ii) SnCl(2)-induced DNA strand breaks were higher than those from UVA and nfo mutant had the slowest repair kinetics; (iii) UVA + SnCl(2) promoted an increase in DNA breaks than SnCl(2) and, again, nfo mutant displayed the slowest repair kinetics. In summary, Nfo protects E. coli cells against damage induced by SnCl(2) and UVA + SnCl(2).


Asunto(s)
Daño del ADN/fisiología , Reparación del ADN/efectos de los fármacos , Reparación del ADN/efectos de la radiación , ADN/efectos de los fármacos , ADN/efectos de la radiación , Desoxirribonucleasa IV (Fago T4-Inducido)/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli , Compuestos de Estaño/administración & dosificación , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Escherichia coli/efectos de la radiación , Especificidad de la Especie , Rayos Ultravioleta
3.
Nucl Med Biol ; 33(7): 915-21, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17045172

RESUMEN

At present, more than 75% of routine nuclear medicine diagnostic procedures use technetium-99m (99mTc). The binding between 99mTc and the drug to obtain the radiopharmaceutical needs a reducing agent, with stannous chloride (SnCl2) being one of the most used. There are controversies about the cytotoxic, genotoxic and mutagenic effects of SnCl2 in the literature. Thus, the approaches below were used to better understand the biological effects of this salt and its association in nuclear medicine kits [methylenediphosphonate (MDP) bone scintigraphy and diethylenetriaminepentaacetic acid (DTPA) kidney and brain scintigraphy]: (i) bacterial inactivation experiments; (ii) agarose gel electrophoresis of supercoiled and linear plasmid DNA and (iii) bacterial transformation assay. The Escherichia coli strains used here were AB1157 (wild type) and BW9091 (xthA mutant). Data obtained showed that both MDP and SnCl2 presented a high toxicity, but this was not observed when they were assayed together in the kit, thereby displaying a mutual protect effect. DTPA salt showed a moderate toxicity, and once more, the DTPA kit provided protection, compared to the SnCl2 effect alone. The results suggest a possible complex formation, either MDP-SnCl2 or DTPA-SnCl2, originating an atoxic compound. On the other hand, SnCl2-induced cell inactivation and the decrease in bacterial transformation generated by DTPA found in XthA mutant strain suggest that the lack of this enzyme could be responsible for the effects observed, being necessary to induce DNA damage repair.


Asunto(s)
ADN Bacteriano/efectos de los fármacos , Escherichia coli/citología , Escherichia coli/efectos de los fármacos , Medicina Nuclear/instrumentación , Juego de Reactivos para Diagnóstico , Compuestos de Estaño/administración & dosificación , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Escherichia coli/genética , Pruebas de Mutagenicidad , Mutación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA