Limas rotatorias de uso en Odontopediatría: revisión de la literatura / Rotary files for use in pediatric dentistry: Literature review

Introducción: Los dientes primarios juegan un importante papel en el crecimiento y desarrollo general de los niños, por lo que es necesario conservarlos hasta el momento de su recambio fisiológico. Cuando existe una afectación pulpar que compromete la vitalidad del diente, la pulpectomía se convierte en un reto para el odontopediatra debido a la compleja anatomía radicular de los dientes primarios. En esta revisión bibliográfica se darán a conocer diferentes sistemas de limas usados en odontopediatría, y así brindar una mirada actualizada de la instrumentación rotatoria al realizar pulpectomías en los molares primarios. Material y Método: se realizó una búsqueda bibliográfica en Pubmed y Web of Science de acuerdo con criterios de inclusión y exclusión previamente establecidos. Resultados: tras aplicar los criterios de inclusión y exclusión fueron seleccionados un total de 30 referencias bibliográficas de los últimos 15 años. Conclusión: las limas rotatorias pediátricas pueden considerarse alternativas seguras y más eficientes en la realización de pulpectomías en molares primarios, ya que se reduce el tiempo de tratamiento, se produce desbridamiento completo de los conductos y se mantiene la función del diente hasta su exfoliación. (AU)

Introduction: Primary teeth play an important role in the growth and development of children, so it is necessary to keep them until the moment of their physiological replacement. When there is a pulp involvement that compromises the vitality of the tooth, pulpectomy treatment becomes a challenge for the pediatric dentist due to the complex root anatomy of primary teeth. This review of the literature will present different file systems used in primary teeth and provide an updated look at rotary instrumentation when performing pulpectomies on primary molars. Material and Method: a bibliographic search was carried out in Pubmed and Web of Science according to previously established inclusion and exclusion criteria. Results: after applying the inclusion and exclusion criteria, a total of 30 bibliographic references from the last 15 years were selected. Conclusion: pediatric rotary files can be considered safe and more efficient alternatives in performing pulpectomies on primary molars, due to treatment time is reduced, complete debridement of the root canals is produced, and tooth function is maintained until exfoliation. (AU)

Modeling the role of the thalamus in resting-state functional connectivity: Nature or structure.

The thalamus is a central brain structure that serves as a relay station for sensory inputs from the periphery to the cortex and regulates cortical arousal. Traditionally, it has been regarded as a passive relay that transmits information between brain regions. However, recent studies have suggested that the thalamus may also play a role in shaping functional connectivity (FC) in a task-based context. Based on this idea, we hypothesized that due to its centrality in the network and its involvement in cortical activation, the thalamus may also contribute to resting-state FC, a key neurological biomarker widely used to characterize brain function in health and disease. To investigate this hypothesis, we constructed ten in-silico brain network models based on neuroimaging data (MEG, MRI, and dwMRI), and simulated them including and excluding the thalamus, and raising the noise into thalamus to represent the afferences related to the reticular activating system (RAS) and the relay of peripheral sensory inputs. We simulated brain activity and compared the resulting FC to their empirical MEG counterparts to evaluate model's performance. Results showed that a parceled version of the thalamus with higher noise, able to drive damped cortical oscillators, enhanced the match to empirical FC. However, with an already active self-oscillatory cortex, no impact on the dynamics was observed when introducing the thalamus. We also demonstrated that the enhanced performance was not related to the structural connectivity of the thalamus, but to its higher noisy inputs. Additionally, we highlighted the relevance of a balanced signal-to-noise ratio in thalamus to allow it to propagate its own dynamics. In conclusion, our study sheds light on the role of the thalamus in shaping brain dynamics and FC in resting-state and allowed us to discuss the general role of criticality in the brain at the mesoscale level.

Particularidades del funcionamiento afectivo-motivacional de pacientes prediabéticos / Particularities of the motivational and affective functioning in prediabetic patients

Introducción: La prevención en el progreso de la prediabetes hacia la diabetes, debe hacerse desde un enfoque holístico y considerar el funcionamiento afectivo - motivacional de quienes la padecen. Objetivo: Determinar las particularidades del funcionamiento afectivo - motivacional de pacientes prediabéticos. Métodos: Se desarrolló un estudio exploratorio descriptivo con metodología mixta, se integraron los análisis cuantitativo y cualitativo; la muestra quedó conformada por 10 sujetos prediabéticos. Para la pesquisa se realizó el análisis psicológico de los pacientes, según su historia clínica y se aplicaron el Registro de la Actividad. Método Directo e Indirecto (RAMDI), la Escala Dembo-Rubinstein, las Técnicas de Completamiento de Frases y de Composición, así como la entrevista semiestructurada. Resultados: Los sujetos prediabéticos no se reconocen como enfermos, no valoran los riesgos que contraen por esa condición y no se comprometen con un cambio de estilo de vida. Conclusiones: En los pacientes prediabéticos la categoría salud no es un motivo rector que oriente y regule su conducta de modo estable; predominó la actitud de «no aceptación de la enfermedad», con una marcada tendencia a la autovaloración inadecuada que limita la responsabilidad personal ante la condición mórbida.

Introduction: the prevention of the progression from prediabetes to diabetes must be done from a holistic approach considering the motivational and affective functioning of the patients who suffer from this condition. Objective: to determine the particularities of the motivational and affective functioning of prediabetic patients. Methods: a descriptive exploratory study was carried out with a mixed-method research where quantitative and qualitative analyzes were integrated; the sample was made up of 10 prediabetic subjects. A psychological assessment was made based on their clinical history and the Register of the Activity. Direct and Indirect Method (RAMDI in Spanish), the Dembo-Rubinstein Scale, the Sentence Completion and the Composition Techniques, as well as the semi-structured interview were applied for screening. Results: the prediabetic subjects do not recognize themselves as sick, do not value the risks they incur with their condition, and do not commit to a lifestyle change. Conclusions: health category in prediabetic patients is not a guiding motive that guides and regulates their behaviour in a stable way; a predominance of an attitude of "non-acceptance of the disease", with a marked tendency to inadequate self-assessment that limited personal responsibility for the morbid condition.

Production of Encecalin in Cell Cultures and Hairy Roots of Helianthella quinquenervis (Hook.) A. Gray.

Plant cell and organ cultures of Helianthella quinquenervis, a medicinal plant whose roots are used by the Tarahumara Indians of Chihuahua, Mexico, to relieve several ailments, were established to identify and quantify some chromenes with biological activity, such as encecalin, and to evaluate their potential for biotechnological production. Gas chromatography-mass spectrometry (GC-MS) analysis corroborated the presence of quantifiable amounts of encecalin in H. quinquenervis cell cultures (callus and cell suspensions). In addition, hairy roots were obtained through three transformation protocols (prick, 45-s sonication and co-culture), using wild type Agrobacterium rhizogenes A4. After three months, cocultivation achieved the highest percentage of transformation (66%), and a comparable production (FW) of encecalin (110 µg/g) than the sonication assay (120 µg/g), both giving far higher yields than the prick assay (19 µg/g). Stable integration of rolC and aux1 genes in the transformed roots was confirmed by polymerase chain reaction (PCR). Hairy roots from cocultivation (six months-old) accumulated as much as 1086 µg/g (FW) of encecalin, over three times higher than the cell suspension cultures. The production of encecalin varied with growth kinetics, being higher at the stationary phase. This is the first report of encecalin production in hairy roots of H. quinquenervis, demonstrating the potential for a future biotechnological production of chromenes.

Exposición al metilmercurio en la población general; toxicocinética; diferencias según el sexo, factores nutricionales y genéticos / Methylmercury exposure in the general population; toxicokinetics; differences by gender, nutritional and genetic factors

El mercurio es un tóxico ambiental que causa numerosos efectos adversos en la salud humana y en los ecosistemas naturales. Los factores que determinan la aparición de efectos adversos y su severidad son entre otros: la forma química del mercurio (elemental, inorgánico, orgánico), la dosis, la edad, la duración de la exposición, la vía de exposición y los factores ambientales, nutricionales y genéticos. En el ciclo acuático del mercurio, una vez que se ha depositado, se transforma en metilmercurio por la acción de determinadas bacterias sulfato reductoras y se bioacumula en los organismos acuáticos incorporándose a la cadena trófica de alimentos. El contenido de metilmercurio es mayor en las especies depredadoras de mayor tamaño y que viven más años como el emperador, pez espada, tiburón, atún o marlín. El metilmercurio se halla unido a las proteínas del pescado por lo que no se elimina mediante la limpieza ni el cocinado del mismo. El feto en desarrollo y los niños pequeños son los más vulnerables a los efectos neurotóxicos del metilmercurio procedente de la ingesta de pescado contaminado. El metilmercurio se absorbe en el tracto gastrointestinal y atraviesa la barrera hematoencefálica y la placenta. Algunos componentes de la dieta como los ácidos grasos poliinsaturados, el selenio, la fibra, los compuestos tiol, algunos fitoquímicos y otros nutrientes pueden modificar la bioaccesibilidad del mercurio y su toxicidad. Además de los factores ambientales, los factores genéticos pueden influir en la toxicidad del mercurio y explicar parte de la vulnerabilidad individual (AU)

Mercury is an environmental toxicant that causes numerous adverse effects on human health and natural ecosystems. The factors that determine the existance of adverse effects, as well as their severity are, among others: the chemical form of mercury (elemental, inorganic, organic), dosis, age, period of exposure, pathways of exposure and environmental, nutritional and genetic factors. In the aquatic cycle of mercury, once it has been deposited, it is transformed into methylmercury due to the action of certain sulphate-reducing bacteria, which bioaccumulates in the aquatic organisms and moves into the food chain. The methylmercury content of large, long-lived fish such as swordfish, shark, tuna or marlin, is higher. Methylmercury binds to protein in fish and is therefore not eliminated by cleaning or cooking the fish. Fetuses and small children are more vulnerable to the neurotoxic effects of methylmercury from the consumption of contaminated fish. Methylmercury is absorbed in the gastrointestinal tract and crosses the blood-brain barrier and the placenta. The intake of certain dietary components such as polyunsaturated fatty acids, selenium, fiber, thiol compounds, certain phytochemicals and other nutrients can modify methylmercury bioaccesibility and its toxicity. Apart from environmental factors, genetic factors can influence mercury toxicity and explain part of the individual vulnerability (AU)

Real-time polarimetric optical sensor using macroporous alumina membranes.

We report on the demonstration of real-time refractive index sensing within 60 µm thick free-standing macroporous alumina membranes with pore diameters of 200 nm. The free-standing macroporous alumina membranes allow the analytes to flow through the pores for targeted delivery, resulting in fast sensing responses. The polarimetric measurement platform exploits the optical anisotropy of the membranes in monitoring the refractive index variations of the analytes that fill the pores, providing highly sensitive and real-time measurements. The experimental characterization of the membranes' birefringence at wavelengths of 808, 980, and 1500 nm showed a decrease in birefringence for shorter wavelengths caused by the depolarization process that takes place when polarized light passes through a porous medium. Volumetric sensing experiments performed at the same wavelengths demonstrated detection limits of 8.1×10(-6), 5.2×10(-6), and 6×10(-6) refractive index units at wavelengths of 808, 980, and 1500 nm, respectively.

Habituation and dehabituation to dichlobenil: simply the equivalent of Penélope's weaving and unweaving process?

The habituation of cell cultures to cellulose biosynthesis inhibitors constitutes a valuable method for learning more about the plasticity of plant cell wall composition and structure. The subculture of habituated cells in the absence of an inhibitor (dehabituation) offers complementary information: some habituation-associated modifications revert, whereas others remain, even after long-term (3-5 years) dehabituation processes. However, is dehabituation simply the opposite to the process of habituation, in the same way that the cloth woven by Penélope during the day was unwoven during the night? Principal Component Analysis applied to Fourier Transformed Infrared (FTIR) spectra of cell walls from dichlobenil-habituated and dehabituated bean cell lines has shown that dehabituation follows a different pathway to that of habituation. Principal component loadings show that dehabituated cells have more pectins, but that these display a lower degree of methyl-esterification, than those of habituated ones. Further analysis of cell walls focusing on the first steps of habituation would serve to identify which specific modifications in pectins are responsible to the fine modulation of cell wall architecture observed during the habituation/dehabituation process.

Effects of alcohol-free beer on lipid profile and parameters of oxidative stress and inflammation in elderly women.

OBJECTIVE: We assessed the influence of alcohol-free beer on factors implicated in atherosclerosis, such as lipid profile, oxidative stress parameters, and proinflammatory cytokines, in postmenopausal women, a population particularly at risk for atherosclerotic disease. METHODS: The study was carried out in 29 nuns, 58 to 73 y old, who live in a convent with a disciplined, regular, and homogeneous lifestyle. The nuns maintained their habits and diet routine, but their meals were supplemented with 500 mL/d of alcohol-free beer (0.0%) divided into two doses over a 45-d period. Lipid profile, inflammatory markers such as C-reactive protein, interleukins 1 and 6, and tumor necrosis factor-alpha, and parameters of oxidative metabolism were determined before and after the study period. RESULTS: There were no differences in the levels of C-reactive protein and proinflammatory cytokines after diet supplementation. The antibody titers to oxidized low-density lipoprotein were significant lower (P < 0.05), and thiobarbituric acid-reactive substances (-18%, P < 0.001) and plasma carbonyl group content (-21%, P < 0.001) were decreased when compared with initial values. Increases in alpha-tocopherol levels (+9%, P < 0.05) and erythrocytic glutathione levels (+29%, P < 0.001) were also noted. With respect to lipid profile, only subjects with cholesterol levels higher than 240 mg/dL showed lower levels after supplementation. CONCLUSION: Consumption of non-alcoholic beer produces a decrease in oxidative stress that can have a beneficial impact on cardiovascular risk; however, the circulating concentrations of inflammatory mediators involved in its pathophysiology remained unchanged.

Glutaric aciduria type II and narcolepsy in pregnancy.

BACKGROUND: Glutaric aciduria type II is a rare disorder affecting the metabolism of fatty acid oxidation and several mitochondrial dehydrogenase enzymes. Narcolepsy and cataplexy is a disorder affecting sleep cycles and rapid eye movement activity. There is little information on outcome or management for either disorder in pregnancy. CASE: This is a case of a 16-year-old with glutaric aciduria type II and narcolepsy with cataplexy, treated with L-carnitine, riboflavin, fluoxetine, and modafinil during pregnancy. Intrapartum management included intravenous carnitine administration, and the patient underwent cesarean delivery at term without complication. CONCLUSION: This inborn error of metabolism and sleep disorder can be effectively treated during pregnancy with nutritional supplementation and stimulants. Because of the risk of cataplexy during labor, cesarean delivery is recommended to minimize the patient's risk.

Identification and characterization of human archaemetzincin-1 and -2, two novel members of a family of metalloproteases widely distributed in Archaea.

Systematic analysis of degradomes, the complete protease repertoires of organisms, has demonstrated the large and growing complexity of proteolytic systems operating in all cells and tissues. We report here the identification of two new human metalloproteases that have been called archaemetzincin-1 (AMZ1) and archaemetzincin-2 (AMZ2) to emphasize their close relationship to putative proteases predicted by bioinformatic analysis of archaeal genomes. Both human proteins contain a catalytic domain with a core motif (HEXXHXXGX3CX4CXMX17CXXC) that includes an archetypal zinc-binding site, the methionine residue characteristic of metzincins, and four conserved cysteine residues that are not present at the equivalent positions of other human metalloproteases. Analysis of genome sequence databases revealed that AMZs are widely distributed in Archaea and vertebrates and contribute to the defining of a new metalloprotease family that has been called archaemetzincin. However, AMZ-like sequences are absent in a number of model organisms from bacteria to nematodes. Phylogenetic analysis showed that these enzymes have undergone a complex evolutionary process involving a series of lateral gene transfer, gene loss, and genetic duplication events that have shaped this novel family of metalloproteases. Northern blot analysis showed that AMZ1 and AMZ2 exhibit distinct expression patterns in human tissues. AMZ1 is mainly detected in liver and heart whereas AMZ2 is predominantly expressed in testis and heart, although both are also detectable at lower levels in other tissues. Both human enzymes were produced in Escherichia coli, and the purified recombinant proteins hydrolyzed synthetic substrates and bioactive peptides, demonstrating that they are functional proteases. Finally, these activities were abolished by inhibitors of metalloproteases, providing further evidence that AMZs belong to this catalytic class of proteolytic enzymes.

Schwannoma antiguo: variante rara de schwannoma / Old schwannomaa. a rare type of schwannoma

OBJETIVO: A propósito de un caso deschwannoma retroperitoneal con características histológicaspoco frecuentes, se evalúa su significación clínica eindicaciones de manejo terapeutico.MÉTODOS: Presentación de un caso de schwannomaretroperitoneal benigno, como hallazgo incidental, alpracticar una Resonancia Magnética, en una paciente de70 años cuya clínica era de una lumbociática de seismeses de evolución. Revisión bibliográfica.RESULTADOS: Tras la exéresis quirúrgica se llegó al diagnósticode schwannoma retroperitoneal antiguo. No seadministra ningún tratamiento complementario. No se haevidenciado recidiva durante seguimiento. Los cambioshistológicos que se ven en los casos de schawannomaantiguo se han interpretado como degenerativos, indicandouna larga evolución, que ha motivado su denominaciónde “antiguos”. Algunos de los casos fueron diagnosticadoscomo malignos.CONCLUSIONES: El schwannoma antiguo es una variantepoco habitual del schwannoma común benigno.Microscópicamente muestra áreas de tejido hipocelular ynúcleos pleomórficos sugestivos de malignidad. Su manejoterapéutico es similar al de otros procesos benginosretroperitoneales, mediante exéresis quirúrgica y seguimiento

OBJECTIVES: We report one case ofretroperitoneal schwannoma with unfrequent histologicalcharacteristics evaluating its clinical significance andtherapeutic options.METHODS: We report the case of a benign retroperitonealschwannoma as an incidental MRI finding in a 70-yearoldfemale patient with symptoms of lumbosciatic painfor 6 months. We perform a bibliographic review.RESULTS: After surgical excision the diagnosis wasretroperitoneal old schwannoma. No additionaltreatment was given. There is no evidence of recurrenceon follow-up. The histological changes apparent in thecases of old schwannoma have been interpreted asdegenerative, indicating a long evolution, which hasmotivated its denomination as old. Some cases havebeen diagnosed as malignant.CONCLUSIONS: The old schwannoma is a rarevariety of the benign common schwannoma.Microscopically its shows areas of hypocellular tissueand pleomorphic nuclei suggestive of malignancy.Therapeutic management is similar to other benignretroperitoneal processes, surgical excision and followup