Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Nature ; 614(7949): 767-773, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36755096

RESUMEN

Cancers arise through the accumulation of genetic and epigenetic alterations that enable cells to evade telomere-based proliferative barriers and achieve immortality. One such barrier is replicative crisis-an autophagy-dependent program that eliminates checkpoint-deficient cells with unstable telomeres and other cancer-relevant chromosomal aberrations1,2. However, little is known about the molecular events that regulate the onset of this important tumour-suppressive barrier. Here we identified the innate immune sensor Z-DNA binding protein 1 (ZBP1) as a regulator of the crisis program. A crisis-associated isoform of ZBP1 is induced by the cGAS-STING DNA-sensing pathway, but reaches full activation only when associated with telomeric-repeat-containing RNA (TERRA) transcripts that are synthesized from dysfunctional telomeres. TERRA-bound ZBP1 oligomerizes into filaments on the outer mitochondrial membrane of a subset of mitochondria, where it activates the innate immune adapter protein mitochondrial antiviral-signalling protein (MAVS). We propose that these oligomerization properties of ZBP1 serve as a signal amplification mechanism, where few TERRA-ZBP1 interactions are sufficient to launch a detrimental MAVS-dependent interferon response. Our study reveals a mechanism for telomere-mediated tumour suppression, whereby dysfunctional telomeres activate innate immune responses through mitochondrial TERRA-ZBP1 complexes to eliminate cells destined for neoplastic transformation.


Asunto(s)
Replicación del ADN , Mitocondrias , Transducción de Señal , Telómero , Humanos , ADN/biosíntesis , ADN/genética , ADN/metabolismo , Mitocondrias/genética , Mitocondrias/metabolismo , Neoplasias/genética , Neoplasias/patología , ARN Largo no Codificante/biosíntesis , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Telómero/genética , Telómero/metabolismo , Interferones , Inmunidad Innata , Autofagia
2.
Nature ; 565(7741): 659-663, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30675059

RESUMEN

Replicative crisis is a senescence-independent process that acts as a final barrier against oncogenic transformation by eliminating pre-cancerous cells with disrupted cell cycle checkpoints1. It functions as a potent tumour suppressor and culminates in extensive cell death. Cells rarely evade elimination and evolve towards malignancy, but the mechanisms that underlie cell death in crisis are not well understood. Here we show that macroautophagy has a dominant role in the death of fibroblasts and epithelial cells during crisis. Activation of autophagy is critical for cell death, as its suppression promoted bypass of crisis, continued proliferation and accumulation of genome instability. Telomere dysfunction specifically triggers autophagy, implicating a telomere-driven autophagy pathway that is not induced by intrachromosomal breaks. Telomeric DNA damage generates cytosolic DNA species with fragile nuclear envelopes that undergo spontaneous disruption. The cytosolic chromatin fragments activate the cGAS-STING (cyclic GMP-AMP synthase-stimulator of interferon genes) pathway and engage the autophagy machinery. Our data suggest that autophagy is an integral component of the tumour suppressive crisis mechanism and that loss of autophagy function is required for the initiation of cancer.


Asunto(s)
Autofagia , Carcinogénesis/genética , Carcinogénesis/patología , Proliferación Celular , Inestabilidad Cromosómica , Autofagia/genética , Puntos de Control del Ciclo Celular , Línea Celular , Cromatina/genética , Cromatina/metabolismo , Cromatina/patología , Inestabilidad Cromosómica/genética , Daño del ADN/genética , Células Epiteliales/metabolismo , Células Epiteliales/patología , Fibroblastos/metabolismo , Fibroblastos/patología , Humanos , Proteínas de la Membrana/metabolismo , Membrana Nuclear/patología , Nucleotidiltransferasas/metabolismo , Telómero/genética , Telómero/patología
3.
Acta Neuropathol ; 147(1): 41, 2024 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-38363426

RESUMEN

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease which currently lacks effective treatments. Mutations in the RNA-binding protein FUS are a common cause of familial ALS, accounting for around 4% of the cases. Understanding the mechanisms by which mutant FUS becomes toxic to neurons can provide insight into the pathogenesis of both familial and sporadic ALS. We have previously observed that overexpression of wild-type or ALS-mutant FUS in Drosophila motor neurons is toxic, which allowed us to screen for novel genetic modifiers of the disease. Using a genome-wide screening approach, we identified Protein Phosphatase 2A (PP2A) and Glycogen Synthase Kinase 3 (GSK3) as novel modifiers of FUS-ALS. Loss of function or pharmacological inhibition of either protein rescued FUS-associated lethality in Drosophila. Consistent with a conserved role in disease pathogenesis, pharmacological inhibition of both proteins rescued disease-relevant phenotypes, including mitochondrial trafficking defects and neuromuscular junction failure, in patient iPSC-derived spinal motor neurons (iPSC-sMNs). In FUS-ALS flies, mice, and human iPSC-sMNs, we observed reduced GSK3 inhibitory phosphorylation, suggesting that FUS dysfunction results in GSK3 hyperactivity. Furthermore, we found that PP2A acts upstream of GSK3, affecting its inhibitory phosphorylation. GSK3 has previously been linked to kinesin-1 hyperphosphorylation. We observed this in both flies and iPSC-sMNs, and we rescued this hyperphosphorylation by inhibiting GSK3 or PP2A. Moreover, increasing the level of kinesin-1 expression in our Drosophila model strongly rescued toxicity, confirming the relevance of kinesin-1 hyperphosphorylation. Our data provide in vivo evidence that PP2A and GSK3 are disease modifiers, and reveal an unexplored mechanistic link between PP2A, GSK3, and kinesin-1, that may be central to the pathogenesis of FUS-ALS and sporadic forms of the disease.


Asunto(s)
Esclerosis Amiotrófica Lateral , Enfermedades Neurodegenerativas , Animales , Humanos , Ratones , Esclerosis Amiotrófica Lateral/patología , Glucógeno Sintasa Quinasa 3/genética , Glucógeno Sintasa Quinasa 3/metabolismo , Proteína Fosfatasa 2/genética , Proteína Fosfatasa 2/metabolismo , Proteína FUS de Unión a ARN/genética , Proteína FUS de Unión a ARN/metabolismo , Enfermedades Neurodegenerativas/patología , Cinesinas/genética , Cinesinas/metabolismo , Neuronas Motoras/metabolismo , Drosophila/genética , Drosophila/metabolismo , Mutación/genética
4.
Nature ; 549(7673): 548-552, 2017 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-28959974

RESUMEN

Classical non-homologous end joining (cNHEJ) and homologous recombination compete for the repair of double-stranded DNA breaks during the cell cycle. Homologous recombination is inhibited during the G1 phase of the cell cycle, but both pathways are active in the S and G2 phases. However, it is unclear why cNHEJ does not always outcompete homologous recombination during the S and G2 phases. Here we show that CYREN (cell cycle regulator of NHEJ) is a cell-cycle-specific inhibitor of cNHEJ. Suppression of CYREN allows cNHEJ to occur at telomeres and intrachromosomal breaks during the S and G2 phases, and cells lacking CYREN accumulate chromosomal aberrations upon damage induction, specifically outside the G1 phase. CYREN acts by binding to the Ku70/80 heterodimer and preferentially inhibits cNHEJ at breaks with overhangs by protecting them. We therefore propose that CYREN is a direct cell-cycle-dependent inhibitor of cNHEJ that promotes error-free repair by homologous recombination during cell cycle phases when sister chromatids are present.


Asunto(s)
Reparación del ADN por Unión de Extremidades/fisiología , Fase G2 , Reparación del ADN por Recombinación/fisiología , Fase S , Línea Celular , Cromátides/genética , Cromátides/metabolismo , Aberraciones Cromosómicas , Roturas del ADN de Doble Cadena , Reparación del ADN por Unión de Extremidades/genética , Fase G1 , Humanos , Autoantígeno Ku/química , Autoantígeno Ku/metabolismo , Unión Proteica , Reparación del ADN por Recombinación/genética , Telómero/genética , Telómero/metabolismo
5.
Anal Bioanal Chem ; 410(27): 7229-7238, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30151686

RESUMEN

A novel platform for carbamate-based pesticide quantification using a chitosan/magnetic iron oxide (Chit-Fe3O4) nanocomposite as a glassy carbon electrode (GCE) modifier is shown for an analytical methodology for determination of bendiocarb (BND). The BND oxidation signal using GCE/Chit-Fe3O4 compared with bare GCE was catalyzed, showing a 37.5% of current increase with the peak potential towards less positive values, showing method's increased sensitivity and selectivity. Using square-wave voltammetry (SWV), calibration curves for BND determination were obtained (n = 3), and calculated detection and quantification limits values were 2.09 × 10-6 mol L-1 (466.99 ppb) and 6.97 × 10-6 mol L-1 (1555.91 ppb), respectively. The proposed electroanalytical methodology was successfully applied for BND quantification in natural raw waters without any sample pretreatment, proving that the GCE/Chit-Fe3O4 modified electrode showed great potential for BND determination in complex samples. ᅟ Graphical abstract.

6.
Phys Chem Chem Phys ; 20(14): 9321-9327, 2018 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-29564421

RESUMEN

The effect of water on the physicochemical properties of an ethylene glycol and choline chloride mixture containing Cu2+ ions was investigated by electrochemical techniques and molecular dynamics simulation. The experiments and computational calculations were carried out by increasing the water content from 0 up to 10% (v/v). The cyclic voltammetry and chronopotentiometry techniques showed that the diffusion coefficient of Cu2+ ions increased and that the peak potentials for both the Cu2+/Cu+ and Cu+/Cu redox couples shifted towards more positive potentials with the increase in the water content in the solution. The molecular dynamics simulation indicated that the water molecules replaced the ethylene glycol molecules that were coordinated with Cu2+ ions, while the interactions between Cu2+ and Cl- ions were not influenced by the presence of water.

7.
Phys Chem Chem Phys ; 18(10): 7242-50, 2016 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-26891224

RESUMEN

The low toxicity and environmentally compatible ionic liquids (ILs) are alternatives to the toxic and harmful cyanide-based baths used in industrial silver electrodeposition. Here, we report the successful galvanostatic electrodeposition of silver films using the air and water stable ILs 1-ethyl-3-methylimidazolium trifluoromethylsulfonate ([EMIM]TfO) and 1-H-3-methylimidazolium hydrogen sulphate ([HMIM(+)][HSO4(-)]) as solvents and AgTfO as the source of silver. The electrochemical deposition parameters were thoughtfully studied by cyclic voltammetry before deposition. The electrodeposits were characterized by scanning electron microscopy coupled with X-ray energy dispersive spectroscopy and X-ray diffraction. Molecular dynamics (MD) simulations were used to investigate the structural dynamic and energetic properties of AgTfO in both ILs. Cyclic voltammetry experiments revealed that the reduction of silver is a diffusion-controlled process. The morphology of the silver coatings obtained in [EMIM]TfO is independent of the applied current density, resulting in nodular electrodeposits grouped as crystalline clusters. However, the current density significantly influences the morphology of silver electrodeposits obtained in [HMIM(+)][HSO4(-)], thus evolving from dendrites at 15 mA cm(-2) to the coexistence of dendrites and columnar shapes at 30 mA cm(-2). These differences are probably due to the greater interaction of Ag(+) with [HSO4(-)] than with TfO(-), as indicated by the MD simulations. The morphology of Ag deposits is independent of the electrodeposition temperature for both ILs, but higher values of temperature promoted increased cluster sizes. Pure face-centred cubic polycrystalline Ag was deposited on the films with crystallite sizes on the nanometre scale. The morphological dependence of Ag electrodeposits obtained in the [HMIM(+)][HSO4(-)] IL on the current density applied opens up the opportunity to produce different and predetermined Ag deposits.

8.
Langmuir ; 30(19): 5645-54, 2014 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-24806390

RESUMEN

Using square-wave voltammetry coupled to the boron-doped diamond electrode (BDDE), it was possible to develop an analytical methodology for identification and quantification of diclofenac (DCL) in tablets and synthetic urine. The electroanalytical procedure was validated, with results being statistically equal to those obtained by chromatographic standard method, showing linear range of 4.94 × 10(-7) to 4.43 × 10(-6) mol L(-1), detection limit of 1.15 × 10(-7) mol L(-1), quantification limit of 3.85 × 10(-7) mol L(-1), repeatability of 3.05% (n = 10), and reproducibility of 1.27% (n = 5). The association of electrochemical techniques with UV-vis spectroscopy, computational simulations and HPLC-ESI/HRMS led us to conclude that the electrooxidation of DCL on the BDDE involved two electrons and two protons, where the products are colorful and easily hydrolyzable dimers. Density functional theory calculations allowed to evaluate the stability of dimers A, B, and C, suggesting dimer C was more stable than the other two proposed structures, ca. 4 kcal mol(-1). The comparison of the dimers stabilities with the stabilities of the molecular ions observed in the MS, the compounds that showed retention time (RT) of 15.53, 21.44, and 22.39 min were identified as the dimers B, C, and A, respectively. Corroborating the observed chromatographic profile, dimer B had a dipole moment almost twice higher than that of dimers A and C. As expected, dimer B has really shorter RT than dimers A and C. The majority dimer was the A (71%) and the C (19.8%) should be the minority dimer. However, the minority was the dimer B, which was formed in the proportion of 9.2%. This inversion between the formation proportion of dimer B and dimer C can be explained by preferential conformation of the intermediaries (cation-radicals) on the surface.


Asunto(s)
Boro/química , Cromatografía Líquida de Alta Presión/métodos , Diamante/química , Diclofenaco/química , Electrodos , Espectrometría de Masa por Ionización de Electrospray/métodos , Simulación por Computador
9.
Children (Basel) ; 11(7)2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-39062230

RESUMEN

BACKGROUND/OBJECTIVES: Child parenting programs can enhance parental skills, prevent future issues in child development, and improve children's quality of life. The present research aimed to study the changes promoted by the Family Education and Support Program (FAF) implemented in Cape Verde, regarding parental educational practices, perceived parental efficacy, and attitudes and beliefs of Cape Verdean parents. METHODS: To this end, 37 participants were evaluated through a pretest-postest design. The evaluated dimensions were perceived parental competence, parenting practices, Parental attitudes and beliefs, mental health and perceived child quality of life. RESULTS: A cluster analysis was conducted, distinguishing two groups. Both groups benefited from the program. Cluster 1 reported more significant gains in dimensions of parental efficacy and satisfaction, inadequate expectations, affection and support, and reactivity, while cluster 2 showed a greater difference in regulation and reactivity. CONCLUSIONS: Overall, the FAF intervention contributed to an increase in positive parenting practices. By analyzing potential underlying profiles in the change process, this study suggests that there are participants who benefit more than others from the intervention, and this information may be relevant for professionals and researchers in the field.

10.
J Mol Graph Model ; 126: 108649, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37820463

RESUMEN

The excess level of carbon dioxide in the atmosphere has contributed a lot to global warming, occasioning several damages to the planet. Therefore, it is urgent to find ways to capture this gas. Then, the present work analyzed the temperature effect in CO2 absorption through deep eutectic solvents (DESs) based on urea and choline chloride using an in silico approach. The Molecular Dynamics (MD) simulations indicated that the increased temperature reduced the interaction potential of carbon dioxide molecules with the DESs components, indicating that the absorption process is more favorable at 303 K. On the other hand, the Noncovalent Interactions (NCI) simulations suggest that the increased temperature reduced the strong attractions and increased repulsive interactions between the carbon dioxide molecules with the solvent analyzed. Therefore, both in silico approaches suggest that the carbon dioxide absorption is more indicated at 303 K.


Asunto(s)
Dióxido de Carbono , Disolventes Eutécticos Profundos , Solventes , Temperatura , Colina
11.
Nanomaterials (Basel) ; 12(14)2022 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-35889592

RESUMEN

The interaction of carbon-based nanomaterials and ionic liquids (ILs) has been thoroughly exploited for diverse electroanalytical solutions since the first report in 2003. This combination, either through covalent or non-covalent functionalization, takes advantage of the unique characteristics inherent to each material, resulting in synergistic effects that are conferred to the electrochemical (bio)sensing system. From one side, carbon nanomaterials offer miniaturization capacity with enhanced electron transfer rates at a reduced cost, whereas from the other side, ILs contribute as ecological dispersing media for the nanostructures, improving conductivity and biocompatibility. The present review focuses on the use of this interesting type of nanocomposites for the development of (bio)sensors specifically for pharmaceutical detection, with emphasis on the analytical (bio)sensing features. The literature search displayed the conjugation of more than 20 different ILs and several carbon nanomaterials (MWCNT, SWCNT, graphene, carbon nanofibers, fullerene, and carbon quantum dots, among others) that were applied for a large set (about 60) of pharmaceutical compounds. This great variability causes a straightforward comparison between sensors to be a challenging task. Undoubtedly, electrochemical sensors based on the conjugation of carbon nanomaterials with ILs can potentially be established as sustainable analytical tools and viable alternatives to more traditional methods, especially concerning in situ environmental analysis.

12.
J Mol Graph Model ; 112: 108137, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35078117

RESUMEN

Deep eutectic solvents (DESs) have many advantages, making them a promising alternative in replacing ionic liquids and organic solvents. Besides, DESs have received much prominence due to their diverse applications: Electrodeposition of metals, organic synthesis, gas adsorption, and biodiesel production. Therefore, this work analyzed the effect of the temperature increase (298 K-353 K) on the behavior of the Co2+ ions in three eutectic solvents through electrochemical techniques and computational simulations. From the electrochemical analysis realized, the increase in temperature caused a reduction in specific mass and an increase in the diffusion coefficient. Besides, the activation energy values were of 15.3, 29.9, and 55.2 kJ mol-1 for 1ChCl:2 EG, 1ChCl:2U, and 1ChCl:2G, respectively. The computational simulations indicate that the increased temperature effect caused the replacement of HBD molecules by anions chloride around Co2+ ions for the SDW1 and SDW3 systems between the temperatures of 298 K-353 K, except for the SDW2 system that the replaced occurred in the interval of 313 K-353 K. Besides, the increase of temperature occasioned the increase of strength for Co-Cl interaction and weakened the interactions between the Co2+ ions with the oxygen of HBD molecules.


Asunto(s)
Líquidos Iónicos , Aniones , Líquidos Iónicos/química , Metales , Solventes/química
13.
Anal Biochem ; 413(2): 148-56, 2011 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-21356193

RESUMEN

The electrochemical reduction behavior of dexamethasone at a hanging mercury drop electrode was investigated by cyclic and square-wave adsorptive voltammetries in a Britton-Robinson buffer at pH 2.0. The optimized experimental conditions consisted of a pulse potential frequency of 100 s(-1), a pulse amplitude of 15 mV, and a potential step height of 2 mV, with E(acc)=-0.60V and t(acc)=15s. From these parameters, it was also possible to develop a detailed study about the kinetic and mechanistic events involved in the reduction process. Two well-defined peaks were observed in the cathodic scan, and peak 2 was used to obtain analytical curves. A linear range between 4.98×10(-8) and 6.10×10(-7)mol L(-1), with a detection limit of 2.54×10(-9)mol L(-1) and a quantification limit of 8.47×10(-9)mol L(-1), was observed. Moreover, it was possible to achieve a simple, selective, and versatile methodology adaptable to the quantification of dexamethasone because common excipients used in multicomponent commercial formulations caused no interference. The satisfactory recoveries and the low relative standard deviation data reflected the high accuracy and precision of the proposed method for the determination of dexamethasone in injectable eye drops and elixir samples.


Asunto(s)
Dexametasona/análisis , Glucocorticoides/análisis , Animales , Combinación de Medicamentos , Electroquímica , Electrodos , Humanos , Concentración de Iones de Hidrógeno , Cinética , Mercurio , Modelos Químicos , Oxidación-Reducción
14.
Anal Methods ; 13(18): 2124-2136, 2021 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-33876058

RESUMEN

A simple and robust sensor (fMWCNT-Nafion®0.5%/GCE) for determination of imidacloprid (IMI), a widely used neonicotinoid, was developed using a glassy carbon electrode (GCE) modified with functionalized multi-walled carbon nanotubes (fMWCNT) and Nafion®. The obtained data suggest that IMI reduction is an irreversible process, due to the reduction of the nitro group to hydroxylamine derivatives, with the participation of two protons and four electrons, and a charge transfer coefficient of 0.141. The optimized square-wave voltammetric conditions were: McIlvaine buffer at pH 6.0, 0.5% of Nafion® in the fMWCNT suspension, -0.6 V and 180 s as accumulation potential and time, respectively. A linearity in the range of 2.00 × 10-7 to 1.77 × 10-6 mol L-1 IMI, with the values of limit of detection and limit of quantification were equal to 3.74 × 10-8 mol L-1 and 1.25 × 10-7 mol L-1, respectively. Repeatability and reproducibility displayed relative standard deviations lower than 5%. Recovery tests performed in tap water, melon, and shrimp yielded mean values of 94 ± 6%, 97 ± 10% and 93 ± 10%, respectively. Moreover, several inorganic and organic compounds did not significantly interfere (0.6 to 4.5%) on the IMI signal, proving the selectivity and applicability of the developed sensor for IMI detection in complex samples.


Asunto(s)
Nanotubos de Carbono , Electrodos , Neonicotinoides , Nitrocompuestos , Reproducibilidad de los Resultados
15.
Nanomaterials (Basel) ; 10(7)2020 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-32610509

RESUMEN

Pharmaceuticals, as a contaminant of emergent concern, are being released uncontrollably into the environment potentially causing hazardous effects to aquatic ecosystems and consequently to human health. In the absence of well-established monitoring programs, one can only imagine the full extent of this problem and so there is an urgent need for the development of extremely sensitive, portable, and low-cost devices to perform analysis. Carbon-based nanomaterials are the most used nanostructures in (bio)sensors construction attributed to their facile and well-characterized production methods, commercial availability, reduced cost, high chemical stability, and low toxicity. However, most importantly, their relatively good conductivity enabling appropriate electron transfer rates-as well as their high surface area yielding attachment and extraordinary loading capacity for biomolecules-have been relevant and desirable features, justifying the key role that they have been playing, and will continue to play, in electrochemical (bio)sensor development. The present review outlines the contribution of carbon nanomaterials (carbon nanotubes, graphene, fullerene, carbon nanofibers, carbon black, carbon nanopowder, biochar nanoparticles, and graphite oxide), used alone or combined with other (nano)materials, to the field of environmental (bio)sensing, and more specifically, to pharmaceutical pollutants analysis in waters and aquatic species. The main trends of this field of research are also addressed.

16.
J Mol Model ; 26(12): 339, 2020 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-33179132

RESUMEN

The water influence on electrochemical behaviour of Ag+ ions in urea and choline chloride mixture was investigated by cyclic voltammetry technique, while the molecular insights about the investigated systems were obtained from molecular dynamic (MD) simulation. The water content was variated from 0 up to 10% (v/v). Cyclic voltammetry technique showed that the peak potential for Ag+/Ag redox couples shifted in direction to more positive potentials with the gradual increase of water content in solution, indicating that the addition of water electrocatalyses the kinetics of the reduction of Ag+ ions. The MD simulations demonstrated that water molecules do not interact strongly with Ag+ ions but induce a small reduction in the number of urea molecules around of the ion and that the water molecules adjust to free spaces in the mixture.

17.
Forensic Sci Int ; 317: 110512, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33002654

RESUMEN

Age estimation is an important procedure in the forensic practice, especially when it comes to the criminal imputability of juvenile offenders. This study aimed to compare two radiographic methods for dental age estimation in a population of subadults from Northeast Brazil considering their performance on allocating individuals below or above the age threshold of 18 years. A cross-sectional observational study was designed. The sample consisted of 1200 panoramic radiographs of Northeastern Brazilian females (n = 600) and males (n = 600) aged between 16 and 21 years. Dental age estimation was performed using the London Atas technique and Cameriere's third molar maturity index (I3M). Statistical tests were performed to assess the sensitivity, specificity and accuracy of the two methods on distinguishing individuals below or above the legal age threshold of 18 years. Considering the total sample, the London Atlas technique reached sensitivity of 92.3%, specificity of 56% and accuracy of 79.9%. I3M revealed sensitivity of 94.1%, specificity of 55.4% and accuracy of 79.8%. Specificity rates systematically decreased when the sample was progressively stratified based on age groups that narrowed close to 18 years. The methods performed very similar (0.878). The combination of methods did not improve the performance on dental age estimation. The London Atlas and the I3M methods similarly distinguished Brazilian individuals as minors or not. Their performance, however, was suboptimal because of the low rates of specificity that could negatively influence on Court decisions. In other words, the methods could wrongly classify minors into the age of legal majority (culminating in false positives). In practice, the misleading classification could restrict individual rights (in the civil scenario) or even support more severe penalties (in the criminal scenario).


Asunto(s)
Determinación de la Edad por los Dientes/métodos , Tercer Molar/crecimiento & desarrollo , Ápice del Diente/crecimiento & desarrollo , Erupción Dental , Diente/crecimiento & desarrollo , Adolescente , Estudios Transversales , Femenino , Humanos , Imagenología Tridimensional , Masculino , Tercer Molar/diagnóstico por imagen , Radiografía Panorámica , Sensibilidad y Especificidad , Diente/diagnóstico por imagen , Ápice del Diente/diagnóstico por imagen , Adulto Joven
18.
J Clin Exp Dent ; 12(8): e736-e744, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32913570

RESUMEN

BACKGROUND: Trauma due to external causes represents one of the greatest challenges for public health services in different regions around the world. This study aimed to determine the prevalence of facial trauma, associated risk factors, and classification of body injuries in individuals who underwent forensic examination in a Brazilian center. MATERIAL AND METHODS: Data were collected at the Ceará State Forensic Medicine unit in a 12-year period. Sociodemographic data related to the etiological agent and lesions resulting from the bodily injury were recorded. RESULTS: Among 1,031 physical injury exams, physical aggression (p<0.001), male victims aged between 21 and 30 years (p<0.001), salaried workers (p<0.001), and soft tissue and dentoalveolar injuries were significant findings. Regarding aggression, domestic violence was prevalent (p<0.001), perpetrated by the victim's partner (p<0.001), using a blunt instrument during the aggression (p<0.001), and directly associated with soft tissue injury (p<0.001). In traffic accidents, the most common type was motorcycle accident (p<0.001), on weekdays (p=0.036), at nighttime (p=0.134), showing a significant association with bone fractures (p=0.001). CONCLUSIONS: Oral and maxillofacial injuries obtained from a Brazilian forensic science center were significantly associated with sociodemographic and etiological factors. Key words:Forensic dentistry, facial trauma, violence, public health.

19.
J Clin Pediatr Dent ; 33(3): 193-7, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19476090

RESUMEN

Enamel defects are common alterations that can occur in both the primary or permanent dentition. A range of etiological factors related to this pathology can be found in the literature. Molar Incisor Hypomineralization (MIH) is a kind of enamel defect alteration that requires complex treatment solutions, and for this reason, it is of great clinical interest for dental practice. This article describes the management of a clinical case of MIH in a 7-year-old child. The different treatment options depending on the extension of the defect, the degree of tooth eruption and the hygiene and diet habits of the patient are also discussed.


Asunto(s)
Hipoplasia del Esmalte Dental/terapia , Restauración Dental Permanente/métodos , Niño , Caries Dental/etiología , Caries Dental/terapia , Hipoplasia del Esmalte Dental/complicaciones , Hipoplasia del Esmalte Dental/patología , Cementos de Ionómero Vítreo , Humanos , Incisivo/anomalías , Masculino , Diente Molar/anomalías , Resinas Sintéticas
20.
Anal Chim Acta ; 1051: 49-57, 2019 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-30661619

RESUMEN

Electroanalytical methodology by boron-doped diamond electrode (BDDE) associated to the square-wave voltammetry (SWV) for the determination of hydrolyzed dipyrone (DIP) in commercial formulations, raw natural waters and in human urine was developed. Through cyclic voltammetry (CV), it was shown that the oxidation of the DIP on the BDDE was irreversible with diffusional control. Computational studies suggested that the oxidation mechanism of DIP occurred with participation of two electrons and one proton. The analytical curves were obtained for concentrations of DIP ranging from 1.0 × 10-6 to 6.5 × 10-5 mol L-1 (r = 0.9994). The values of detection limit (LOD) and quantification limit (LOQ) of DIP were calculated from SWV and found to be 2.6 × 10-7 mol L-1 and 8.8 × 10-7 mol L-1. The methodology was effectively applied to real samples with the values of calculated recoveries varying between 91.0% and 117.3% and validated by iodometric titration experiments whose values were between 93.3% and 106.9%. The proposed methodology with BDDE represents an alternative tool and it has advantageous, such as very easy handling, low cost, no need for modification, low detection limit. Furthermore, it can be used for the routine analysis of DIP in different real samples.


Asunto(s)
Teoría Funcional de la Densidad , Dipirona/química , Electroquímica/métodos , Dipirona/orina , Humanos , Concentración de Iones de Hidrógeno , Límite de Detección , Modelos Moleculares , Conformación Molecular , Oxidación-Reducción
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA