Post-Retained Single Crowns versus Fixed Dental Prostheses: A 7-Year Prospective Clinical Study

Biomechanical integrity of endodontically treated teeth (ETT) is often compromised. Degree of hard tissue loss and type of final prosthetic restoration should be carefully considered when making a treatment plan. The objective of this prospective clinical trial was to assess the influence of the type of prosthetic restoration as well as the degree of hard tissue loss on 7-y clinical performance of ETT restored with fiber posts. Two groups (n = 60) were defined depending on the type of prosthetic restoration needed: 1) single unit porcelain-fused-to-metal (PFM) crowns (SCs) and 2) 3- to 4-unit PFM fixed dental prostheses (FDPs), with 1 healthy and 1 endodontically treated and fiber post-restored abutment. Within each group, samples were divided into 2 subgroups (n = 30) according to the amount of residual coronal tissues after abutment buildup and final preparation: A) >50% of coronal residual structure or B) equal to or <50% of coronal residual structure. The clinical outcome was assessed based on clinical and intraoral radiographic examinations at the recalls after 6, 12, 24, 36, 48, and 84 mo. Data were analyzed by Kaplan-Meier log-rank test and Cox regression analysis (P < 0.05). The overall 7-y survival rate of ETT restored with fiber post and either SCs or FDPs was 69.2%. The highest 84-mo survival rate was recorded in group 1A (90%), whereas teeth in group 2B exhibited the lowest performance (56.7% survival rate). The log-rank test detected statistically significant differences in survival rates among the groups (P = 0.048). Cox regression analysis revealed that the amount of residual coronal structure (P = 0.041; hazard ratio [HR], 2.026; 95% confidence interval [CI] for HR, 1.031–3.982) and the interaction between the type of prosthetic restoration and the amount of residual coronal structure (P = 0.024; HR, 1.372; 95% CI for HR, 1.042–1.806) were statistically significant factors for survival (ClinicalTrials.gov NCT01532947)

Convective heat transfer in cellular ceramic: A 3D numerical solution

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.In this work, three-dimensional thermo fluid dynamics analyses were performed in order to evaluate the convective heat transfer coefficient for cellular ceramics, both random (i.e. foams) and regular (i.e. lattices). The study aimed at evaluating the heat exchange performance of cellular ceramics with the scope of engineering their morphology in order to maximize the ratio between heat exchange and pressure drop. Performed simulations focus on capturing the relevance of cell morphology on thermal convection and pressure drop of cellular ceramics within a porosity range of 75–90% and at different fluid velocities. Computational analyses were performed with the commercial CFD package ANSYS-Fluent. Results show that parameters affecting most the pressure drop are porosity and cell aspect ratio; on the other hand, the thermal convective coefficient is strongly dependent on surface area, which, in turn, is directly related to cell morphology.dc201

Optimal Use of Vitamin D When Treating Osteoporosis

Inadequate serum 25-hydroxyvitamin D (25[OH]D) concentrations are associated with muscle weakness, decreased physical performance, and increased propensity in falls and fractures. This paper discusses several aspects with regard to vitamin D status and supplementation when treating patients with osteoporosis in relation to risks and prevention of falls and fractures. Based on evidence from literature, adequate supplementation with at least 700 IU of vitamin D, preferably cholecalciferol, is required for improving physical function and prevention of falls and fractures. Additional calcium supplementation may be considered when dietary calcium intake is below 700 mg/day. For optimal bone mineral density response in patients treated with antiresorptive or anabolic therapy, adequate vitamin D and calcium supplementation is also necessary. Monitoring of 25(OH)D levels during follow-up and adjustment of vitamin D supplementation should be considered to reach and maintain adequate serum 25(OH)D levels of at least 50 nmol/L, preferably greater than 75 nmol/L in all patients

Investigación, extensión y transferencia: una alianza estratégica para fomentar la participación pública y la conservación de la biodiversidad del estuario del río Gallegos (Santa Cruz)

Los impactos ambientales que amenazan la viabilidad de los ecosistemas y su biodiversidad requieren de una sociedad comprometida y que sea proactiva en la generación de respuestas y ejecución de prácticas amigables con el entorno. El estado crítico del ambiente en que vivimos exige un compromiso por parte de las instituciones educativas, quienes deben formar, informar y reforzar conceptos que nos permitan encaminarnos hacia comunidades sustentables, conjugando una mejor calidad de vida con la conservación de los recursos naturales. Bajo esta concepción, trabajamos desde el año 2000 en la ciudad de Río Gallegos, (ubicada sobre la margen sur del estuario homónimo) en proyectos de investigación y extensión, teniendo como objetivos: contribuir al conocimiento y valorización ecológica del estuario, brindar herramientas para mejorar su manejo, capacitar actores locales, promover el ecoturismo y fomentar la participación pública. Para ello, se desarrollaron actividades articulando acciones junto a instituciones públicas/privadas, ONG locales e internacionales y alumnos universitarios, como ser programas de capacitación, talleres públicos participativos, disertaciones en el Programa de Educación Ambiental Municipal, charlas en establecimientos educativos y reuniones de trabajo con diferentes estamentos políticos, con el fin de analizar propuestas de ordenamiento y manejo del estuario. Se utilizaron estrategias de la educación ambiental para llegar a diferentes público meta, como la realización de cortos documentales, difusión en medios masivos de comunicación, publicación de folletos, afiches, guía de aves, material didáctico interactivo y página web, buscando afianzar el sentido de pertenencia e identidad con el lugar. Entre algunos criterios de éxito alcanzados a partir de la conjugación de investigación/extensión/transferencia, mencionamos: la creación de dos áreas protegidas (provincial y municipal), reconocimiento del estuario como Sitio de Importancia Internacional por la Red Hemisférica de Reservas para Aves Playeras y Área de importancia para la conservación de Aves, promulgación de una ley de conservación de humedales costeros, creación de la Agencia Ambiental Municipal, apertura de la Reserva Costera Urbana de Río Gallegos con puesto de atención para los visitantes, cartelería y senderos interpretativos y la construcción de un Centro de Interpretación Ambiental (inaugurado en diciembre/2011) entre municipio, universidad y Asociación Ambiente Sur. Este nuevo escenario mejora la oferta turístico-recreativa local, otorgando beneficios tangibles a la comunidad. El trabajo conjunto entre diferentes miembros de la comunidad, universidad y organismos del estado resultó clave para avanzar en la conservación de este ecosistema, basado en la promoción de valores sociales y ambientales.

Alterations in Mesenteric Lymph Node T Cell Phenotype and Cytokine Secretion are Associated with Changes in Thymocyte Phenotype after LP-BM5 Retrovirus Infection

In this study, mouse MLN cells and thymocytes from advanced stages of LP-BM5 retrovirus infection were studied. A decrease in the percentage of IL-7+ cells and an increase in the percentage of IL-16+ cells in the MLN indicated that secretion of these cytokines was also altered after LP-BM5 infection. The percentage of MLN T cells expressing IL-7 receptors was significantly reduced, while the percentage of MLN T cells expressing TNFR-p75 and of B cells expressing TNFR-p55 increased. Simultaneous analysis of surface markers and cytokine secretion was done in an attempt to understand whether the deregulation of IFN-Υ secretion could be ascribed to a defined cell phenotype, concluding that all T cell subsets studied increased IFN-Υ secretion after retrovirus infection. Finally, thymocyte phenotype was further analyzed trying to correlate changes in thymocyte phenotype with MLN cell phenotype. The results indicated that the increase in single positive either CD4+CD8- or CD4- CD8+ cells was due to accumulation of both immature (CD3- ) and mature (CD3+) single positive thymocytes. Moreover, single positive mature thymocytes presented a phenotype similar to the phenotype previously seen on MLN T cells. In summary, we can conclude that LP-BM5 uses the immune system to reach the thymus where it interferes with the generation of functionally mature T cells, favoring the development of T cells with an abnormal phenotype. These new T cells are activated to secrete several cytokines that in turn will favor retrovirus replication and inhibit any attempt of the immune system to control infection

Lack of phenotypic and evolutionary cross-resistance against parasitoids and pathogens in Drosophila melanogaster

BackgroundWhen organisms are attacked by multiple natural enemies, the evolution of a resistance mechanism to one natural enemy will be influenced by the degree of cross-resistance to another natural enemy. Cross-resistance can be positive, when a resistance mechanism against one natural enemy also offers resistance to another; or negative, in the form of a trade-off, when an increase in resistance against one natural enemy results in a decrease in resistance against another. Using Drosophila melanogaster, an important model system for the evolution of invertebrate immunity, we test for the existence of cross-resistance against parasites and pathogens, at both a phenotypic and evolutionary level.MethodsWe used a field strain of D. melanogaster to test whether surviving parasitism by the parasitoid Asobara tabida has an effect on the resistance against Beauveria bassiana, an entomopathogenic fungus; and whether infection with the microsporidian Tubulinosema kingi has an effect on the resistance against A. tabida. We used lines selected for increased resistance to A. tabida to test whether increased parasitoid resistance has an effect on resistance against B. bassiana and T. kingi. We used lines selected for increased tolerance against B. bassiana to test whether increased fungal resistance has an effect on resistance against A. tabida.Results/ConclusionsWe found no positive cross-resistance or trade-offs in the resistance to parasites and pathogens. This is an important finding, given the use of D. melanogaster as a model system for the evolution of invertebrate immunity. The lack of any cross-resistance to parasites and pathogens, at both the phenotypic and the evolutionary level, suggests that evolution of resistance against one class of natural enemies is largely independent of evolution of resistance against the other

Highly efficient production of rabies virus glycoprotein G ectodomain in Sf9 insect cells

In the present study, we developed a complete process to produce in insect cells a high amount of the ectodomain of rabies virus glycoprotein G (GE) as suitable antigen for detecting anti-rabies antibodies. Using the baculovirus expression vector system in Sf9 insect cells combined with a novel chimeric promoter (polh-pSeL), the expression level reached a yield of 4.1± 0.3 mg/L culture, which was signifcantly higher than that achieved with the standard polh promoter alone. The protein was recovered from the cell lysates and easily purifed in only one step by metal ion afnity chromatography, with a yield of 95% and a purity of 87%. Finally, GE was successfully used in an assay to detect specifc antibodies in serum samplesderived from rabies-vaccinated animals. The efcient strategy developed in this work is an interesting method to produce high amounts of this glycoprotein.Fil: Targovnik, Alexandra Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: Ferrari, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Mc Callum, Gregorio Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: Arregui, Mariana Bernadett. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: Smith, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: Bracco, Lautaro Fidel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: Alfonso, Victoria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: López, María Gabriela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Martínez Solís, María. Universidad de Valencia. Estructura de Investigación Interdisciplinar en Biotecnología y Biomedicina; EspañaFil: Herrero, Salvador. Universidad de Valencia. Estructura de Investigación Interdisciplinar en Biotecnología y Biomedicina; EspañaFil: Miranda, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; Argentin