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RESUMEN: En la historia de la Endodoncia, se han utilizado distintos métodos para determinar la longitud de los canales radiculares, como sensación táctil y radiografías. Últimamente, han adquirido gran importancia los localizadores apicales electrónicos, por su gran precisión. Actualmente se ha incorporado el uso de imagenología con Cone Beam. Debido a que existen muchas formas de medir dicha longitud, es necesario ponerlos a prueba y ver si se asemejan a la técnica gold estándar definida en la literatura como el localizador electrónico de foramen apical. El propósito de esta investigación es determinar si existen diferencias estadísticamente significativas en la medida de la longitud de trabajo entre el localizador electrónico de foramen apical, y el uso de Cone Beam procesado con el software 3D endo de Dentsply Sirona. Para esto, se seleccionaron 30 premolares extraídos; se les tomó un Cone Beam para ser analizados con el software 3D endo y medir la longitud de trabajo. Una vez hecho esto, se realizó manualmente cavidad de acceso y se preparó el tercio cervical con fresas Gates Glidden 1 y 2; luego, los dientes fueron colocados en un modelo Pro Train, que asemejó las propiedades de los dientes en la cavidad oral, para permitir el uso del localizador electrónico de foramen y determinar la longitud de trabajo. Una vez obtenidos los datos, fueron comparados a través del Test de Proporciones (p=0.05 hipotético), dando como resultado p=0,2 lo que indica que no existen diferencias estadísticamente significativas en la medida de la longitud de trabajo entre ambos métodos.

ABSTRACT: Various methods have been used in the history of endodontics, to determine the length of the root canals (working length), such as tactile sensation and X-rays. Recently, apical locators have acquired importance, due to their precision. The use of Cone Beam has now also been incorporated. Because there are many ways to measure this length, it is necessary to test them and see if they resemble the standard gold measurement technique defined in the literature as the electronic apex locators. The purpose of this research is to determine whether there are statistically significant differences in the working length between the electronic apex locators, and the use of Cone Beam processed with the Software 3D Endo by Dentsply Sirona. For this, 30 extracted pre-molars were selected, for Cone Beam tomography and 3D endo Software analysis, to measure the working length. Once this was carried out, cavity preparation was performed manually, and the cervical third approached with gates glidden drills 1 and 2. Subsequently, the teeth were placed in a Pro Train model, which resembled the properties of the teeth in the oral cavity, to allow the use of the electronic apex locators to determine the working length.Once the data were obtained, they were compared through the proportions Test (p = 0.05 hypothetical), resulting in p = 0.2, indicating that there are no statistically significant differences in the working length between the two methods.

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Epidemiological studies have shown that air particulate matter (PM) can increase respiratory morbidity and mortality being the lungs the main target organ to PM body entrance. Even more, several in vivo and in vitro studies have shown that air PM has a wide toxicity spectra depending among other parameters, on its size, morphology, and chemical composition. The Reconquista River is the second most polluted river from Buenos Aires, and people living around its basin are constantly exposed to its contaminated water, soil and air. However, the air PM from the Reconquista River (RR-PMa) has not been characterized, and its biological impact on lung has yet not been assessed. Therefore, the present investigation was undertaken to study (1) RR-PMa morphochemical characteristic and (2) RR-PMa lung acute effects after intranasal instillation exposure through the analysis of three end points: oxidative stress, inflammation, and apoptosis. A single acute exposure of RR-PMa (1 mg/kg body weight) after 24 h caused significant (p < 0.05) enrichment in bronchoalveolar total cell number and polymorphonuclear (PNM) fraction, superoxide anion generation, production of pro-inflammatory cytokines TNF-α and IL-6, and induction of apoptosis. It was also observed that in lung homogenates, none of the antioxidant enzymes assayed showed differences between exposed RR-PMa and control mice. These data demonstrate that air PM from the Reconquista River induce lung oxidative stress, inflammation, and cell death therefore represents a potential hazard to human health.

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Müller cells are not only the main glial cell type in the retina but also latent progenitor/stem cells, which in pathological conditions can transdifferentiate to a neuronal phenotype and regenerate the neurons lost in a mature retina. Several signal transduction pathways can induce the dedifferentiation of mature Müller cells to a progenitor-like state, including that stimulated by glutamate. However, the precise molecular mechanisms by which terminally differentiated cells are initially primed to acquire multipotency remain unclear. In the present study, we have characterized early genetic and epigenetic events that occur immediately after glutamate-induced dedifferentiation of fully differentiated Müller cells is initiated. Using Müller cell-enriched cultures from postnatal rats, we demonstrate that glutamate triggers a rapid dedifferentiation response characterized by changes in cell morphology coupled to the induction of progenitor cell marker gene expression (e.g., nestin, lin28 and sox2) within 1h. Dedifferentiation involved the activation of N-methyl-d-aspartate and type II metabotropic glutamate receptors, as well as global DNA demethylation (evident through the decrease in methyl-CpG-binding protein 2 immunoreactivity) and an increase in gadd45-ß gene expression; although, early progenitor gene expression was only partially inhibited by pharmacological impairment of DNA methylation. Importantly, the expression of Müller glia identity genes (i.e., glutamine synthetase; cellular retinaldehyde binding protein, CRALBP) is retained through the process. Dedifferentiated Müller cells held an early neuronal differentiation potential similar to that observed in retinal progenitor-enriched cultures but, contrary to the latter, dedifferentiated Müller cells failed to further differentiate into mature photoreceptor lineages. We speculate that, in spite of the initial triggering of the dedifferentiation pathways, these cells may exhibit a certain degree of epigenetic memory that precludes them from further differentiation.

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Retinogenesis is a developmental process that involves the sequential formation of neurons and glia from retinal progenitors. Once retinogenesis is completed, Müller glial cells can be stimulated to differentiate into neuronal lineages and constitute a retina-intrinsic source of neural progenitors. The identification of the intrinsic and extrinsic factors that control proliferation and differentiation of Müller cells or retinal progenitors is needed in order to fully define their potential therapeutic use in regenerative approaches. Here we determined the response of retinal progenitors derived from Müller glia primary cell cultures to GABA-activated signal transduction cascades. Using Western blot analysis, immunocytochemistry and calcium imaging we found that GABA induces an increase of the number of progenitor cells that present spontaneous intracellular calcium transients as well as their frequency, which involve the participation of L-type voltage-gated calcium channels (VGCCs). This process correlates with the activation of transcription factor CREB through Ser33 phosphorylation and the induction of expression of the early neuronal markers NeuroD1 and ßIII-tubulin. GABA-mediated CREB phosphorylation was rapid and sustained and the pharmacological blockade of CREB activity inhibited the effect of GABA on NeuroD1 expression. Furthermore, consistent with the role of CREB as a histone acetyltransferase recruiter, we demonstrate that GABA induces the modification of histone H4 acetylation pattern in these cells suggesting that epigenetic alterations participate in the differentiation process. Our results support the notion that postnatal retinal progenitors derived from Müller glia primary cell cultures respond to GABA through the same molecular pathway previously characterized in hippocampal progenitors and developing neurons. We speculate that the induction of GABA receptor signaling could represent a novel strategy to enhance neural versus glial specification from these cells through genetic and epigenetic mechanisms.

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En el marco del proyecto "Pediatría ambulatoria itinerante para comunidades rurales y aisladas" (P.A.I.C.R.A.) diagramado por LA HIGUERA.ONG en cooperación con el Laboratorio de Villa Río Bermejito y Sistema de Salud de provincia de Chaco; entre los meses de julio a diciembre de 2007 se realizó el relevamiento serológico en el área programática correspondientes a Villa Río Bermejito y El Espinillo del Monte Impenetrable (Zona Sanitaria VI) de la provincia de Chaco. En este área viven alrededor 9200 personas pertenecientes a comunidades de pueblos originarios (tobas) y criollos, que ocupan un área geográfica de 4000 km2, en la cual las condiciones sociosanitarias son propicias para el desarrollo de esta enfermedad. Se realizaron 1296 serologías para la enfermedad de Chagas con sangre extraída por venopunción. Se utilizaron 3 técnicas de procesamiento diferentes: hemaglutinación indirecta (HAI, Chagas Polycraro S.A.I.C), enzimainmunoensayo (ELISA Chagas Test, Wienner lab) e Inmuno fluorescencia Indirecta (IFI). Se consideraron positivas las muestras que fueron reactivas por dos técnicas serológicas. Se obtuvo evidencia serológica de infección por Tripanosoma Cruzi en 529(40,8%) de 1296 personas, en el grupo de edad de 0-15 años en 191 (29%); y en los menores de 5 años de 44(22,2%). Los datos obtenidos muestran un escaso control vectorial con valores muy similares a estudios previos que se hicieron en esta misma área hace siete años. Un dato preocupante es que el 66,6% de las mujeres en edad fértil está infectada, lo que lleva a predecir un alto riesgo de chagas congénito. Este trabajo demuestra que son imprescindibles políticas sanitarias sostenidas en el tiempo, con equipos de trabajo con funciones preestablecidas destinadas por un lado al control del vector y por otro al diagnóstico, tratamiento y seguimiento en toda el área endémica, por profesionales especializados, preferentemente del área pediátrica (AU)

Within the framework of the project "Itinerary outpatient pediatrics for rural and isolated communities" (P.A.I.C.R.A.) created by LA HIGUERA.ONG in cooperation with the Laboratory of Villa Río Bermejito and the Chaco Health System, a serological survey was conducted in the study area of Villa Río Bermejito and El Espinillo del Monte Impenetrable (Sanitary zone VI) in the province of Chaco between July and December 2007. The area has around 9200 inhabitants belonging to indigenous (tobas) and immigrant-descendant communities and covers 4000 km2 where socio-sanitary conditions favor the spread of Chagas disease. By venipuncture, 1296 blood samples were drawn to be evaluated for Chagas disease. Three different techniques were used: indirect hemagglutination assay (IHA, Chagas Polycraro S.A.I.C), enzyme-linked immunosorbent assay (ELISA Chagas Test, Wienner lab), and indirect immunofluorescence assay (IFA). Samples that showed reactivity in at least two techniques were considered positive. Serological evidence of infection by Trypanosoma cruzi was found in 529 (40.8%) of 1296 persons; 191 (29%) in the age group of 0-15 years and 44 (22.2%) under 5 years of age. The data show poor vectorial control and values similar to studies conducted in the same area 7 years previously. Worrisome is the fact that 66.6% of women of child-bearing age are infected, leading to a high risk of congenital Chagas disease in the future. The present study shows that preventive policies sustained over time are necessary with teams working both on vector control and diagnosis, treatment, and follow-up of patients in endemic areas consisting of specialized health care workers, preferably in the field of pediatrics (AU)

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