ABSTRACT Introduction: Fiberglass posts often fall off their position due to loss of adhesive capacity when they are subjected to masticatory force. Objective: Compare in vitro the tensile bond strength of fiberglass and anatomized posts cemented with the same adhesive material. Methods: An in vitro experimental study was conducted. A selection was made of 20 premolars extracted by orthodontic indication which were then randomly distributed into two groups. The premolars underwent root canal treatment by a specialist. The preparation was manual and sealing was performed by lateral condensation. The teeth were prepared in the standard manner to receive the fiberglass and resin-anatomized posts. In both groups’ cementation followed the protocol suggested by the manufacturer of Allcem Core® (dual cement). The specimens were stamped in self-curing acrylic. Next, they were subjected to vertical tensile strength in an materials testing machine (Instrom©). Results: The mean values obtained were 31 kg/F for teeth with anatomized posts and 12.47 kg/F for fiberglass posts. According to Shapiro-Wilk tests, the samples exhibited a normal distribution (p > 0.05). The hypothesis was contrasted with Student’s t test, obtaining a highly significant statistical difference between the groups (p = 0.001). Conclusions: Vertical tensile bond strength is greater in anatomized posts.

RESUMEN Introducción: Es frecuente el desprendimiento de los espigos de fibra de vidrio por pérdida de adhesión cuando son sometidos a las fuerzas masticatorias. Objetivo: Comparar in vitro la resistencia a las fuerzas de tracción de espigos de fibra de vidrio y anatomizado con un mismo cemento. Métodos: Estudio in vitro, de tipo experimental. Se seleccionaron 20 premolares extraídos por motivos ortodónticos que fueron distribuidos aleatoriamente en dos grupos. Se les realizó el tratamiento de conductos por un especialista, la preparación fue manual y la técnica de obturación por condensación lateral. Los dientes fueron preparados para, en forma estándar, recibir el espigo de fibra de vidrio y anatomizados con resina. Para ambos grupos la cementación siguió el protocolo sugerido por el fabricante de Allcem Core® (cemento dual). Los especímenes fueron troquelados en acrílico de autocurado. Para luego ser sometido a fuerza de tracción vertical en la máquina de pruebas de materiales (Instrom©). Resultados: En el grupo de dientes con espigos anatomizados se obtuvo una media de 31 Kg/F, postes de fibra de vidrio 12,47 Kg/F. Según las pruebas de Shapiro-Wilk, las muestras presentaron distribución normal (p > 0,05). Se contrastó la hipótesis con la prueba de t de Student y se encontró diferencia estadística altamente significativas entre los grupos (p = 0,001) Conclusiones: Existe una mayor resistencia a la tracción vertical en los espigos anatomizados.

The hemophagocytic syndrome represents an infrequent, occasionally misdiagnosed and usually fatal heterogeneous entity. Infections, drugs, autoimmune diseases and cancer are often triggers of the secondary hemophagocytic syndrome. Its physiopathogenic mechanism is explained by an impaired and inefficacious function of the NK and T cytotoxic cells that leads to an ineffective and uncontrolled immune response, inducing cellular damage, multiorganic failure with macrophage proliferation and hemophagocytosis. The main objective of the different therapeutic options, commonly combinations of steroids and chemotherapy, is the suppression of the uncontrolled immune response. Occasionally, the clinical condition of some patients represents a contraindication for intensive treatment. We report a case of a severely burned patient that fulfilled the revised criteria for the hemophagocytic syndrome and was successfully treated with the combination of intravenous immunoglobulins and steroids.

El síndrome hemofagocítico constituye una entidad infrecuente, heterogénea, subdiagnosticada, y muchas veces fatal. En los casos secundarios, los desencadenantes pueden ser numerosos, tales como infecciones, fármacos, enfermedades autoinmunes y neoplasias. El mecanismo fisiopatogénico se explica por la presencia de una función disminuida o defectuosa de células NK y linfocitos T citotóxicos, que resulta en una activación inmune inefectiva y descontrolada, conduciendo al daño celular, falla multiorgánica y proliferación macrofágica con hemofagocitosis. Existen diferentes opciones terapéuticas, mayormente combinaciones de citostáticos y esteroides, cuyo objetivo es la supresión de la respuesta inmune descontrolada. Ocasionalmente, la condición clínica de algunos pacientes con síndrome hemofagocítico impide la utilización de esquemas terapéuticos intensivos. Comunicamos el caso de un paciente quemado grave, que reúne los criterios diagnósticos de síndrome hemofagocítico, quien presentó una evolución favorable con el tratamiento combinado de esteroides e inmunoglobulinas endovenosas.

Cells tightly regulate iron levels through the activity of iron regulatory proteins (IRPs) that bind to RNA motifs called iron responsive elements (IREs). When cells become iron-depleted, IRPs bind to IREs present in the mRNAs of ferritin and the transferrin receptor, resulting in diminished translation of the ferritin mRNA and increased translation of the transferrin receptor mRNA. Similarly, body iron homeostasis is maintained through the control of intestinal iron absorption. Intestinal epithelia cells sense body iron through the basolateral endocytosis of plasma transferrin. Transterrin endocytosis results in enterocytes whose iron content will depend on the iron saturation of plasma transferrin. Cell iron levels, in turn, inversely correlate with intestinal iron absorption. In this study, we examined the relationship between the regulation of intestinal iron absorption and the regulation of intracellular iron levels by Caco-2 cells. We asserted that IRP activity closely correlates with apical iron uptake and transepithelial iron transport. Moreover, overexpression of IRE resulted in a very low labile or reactive iron pool and increased apical to basolateral iron flux. These results show that iron absorption is primarily regulated by the size of the labile iron pool, which in turn is regulated by the IRE/IRP system.

Eosinophils have long been thought to be effectors of immunity to helminths but have also been implicated in the pathogenesis of asthma. Patterns of cytokine production in the host may influence the pathogenesis of these diseases by regulating the activities of eosinophils and other components of the immune response. Mice which constitutively over-express IL-5 have profound and life-long eosinophilia in a restricted number of tissues. Although eosinophils from IL-5 transgenics are functionally competent for a number of parameters considered to be important in inflammation, untreated animals are overtly normal and free of disease. In addition, the responses of these animals when exposed to aeroallergens and helminths present a number of apparent paradoxes. Eosinophil accumulation in tissues adjacent to major airways is rapid and extensive in transgenics exposed to the aeroallergen, but even after treatment with antigen over many months these mice show no evidence of respiratory distress or pathology. Helminth-infected IL-5 transgenics and their non-transgenic littermates develop similar inflammatory responses at mucosal sites and are comparable for a number of T cell and antibody responses, but they differ considerably in their ability to clear some parasite species. The life-cycle of Nippostrongylus brasiliensis is significantly inhibited in IL-5 transgenics, but that of Toxocara canis is not. Our results also suggest that eosinophilia and/or over-expression of IL-5 may actually impair host resistance to Schistosoma mansoni and Trichinella spiralis. The pathogenesis of diseases in which eosinophils are involved may therefore be more complex than previously thought.