Comparison of the apple vinegar with other chelating solutions on smear layer and calcium ions removal from the root canal.

Background: The action of endodontic instruments during biomechanical preparation results in smear layer formation. Removing the smear layer enhances disinfection into dentinal tubules in addition to allowing tridimensional sealing of the root canal system. Aim: This study was designed to evaluate the smear layer removal and quantify the calcium ion release resulting from final irrigation with different chelating solutions. Materials and Methods: Fifty human canines were instrumented and the final irrigation was performed with apple vinegar, 5% malic acid, 5% acetic acid, 17% ethylenediamine tetraacetic acid (EDTA), and distilled water (control), which were collected and analyzed by atomic absorption spectrometry to quantify the concentration of calcium ions released. Smear layer removal was assessed in the cervical, middle, and apical thirds by SEM. Results: There was statistically significant difference (P < 0.001) between 17% EDTA and the other solutions with regard to smear layer removal. Apple vinegar, 5% malic acid, and 5% acetic acid promoted similar root canal cleaning. There was no statistical difference among the root canal thirds. The highest concentrations of calcium ions were obtained with 17% EDTA (P<0.001) followed by malic acid, apple vinegar, and acetic acid. Apple vinegar and acetic acid removed the smallest quantity of calcium ions. Conclusion: It was concluded that 17% EDTA enabled greater smear layer removal and promoted release of the highest concentrations of calcium ions than the other solutions tested.

Prevalencia de anemia y deficiencia de hierro en escolares jujeños de 12 años / Prevalence of anemia and iron deficiency in 12 year old school children from Jujuy

La deficiencia de hierro es una de las deficiencias de micronutrientes más comunes. Los adolescentes son un grupo vulnerable. Un reconocimiento oportuno puede prevenir una anemia ferropénica, etapa final y grave de dicha deficiencia, insuficientemente conocida en nuestro país. El objetivo de este estúdio fue determinar los valores hematológicos en adolescentes y conocer las prevalencias de anemia y deficiência de hierro. Definidas como a) anemia: hematocrito (Hto) <38%, b) deficiencia componente funcional de hierro: saturación de transferrina <16%, c) deficiencia en los depósitos de hierro: ferritina (Ferr) <15 ng/ml. Se estudiaron 2.265 escolares de 12 años, de ambos sexos, en áreas urbanas y periurbanas de San Salvador de Jujuy (1.250 m.s.n.m.). Se determinaron: Hto, hierro sérico, capacidad total de ligadura de hierro a la transferrina por colorimetría y Ferr por ELISA. No se encontró anemia en la población estudiada. La ferrodeficiencia se observo en el componente funcional de hierro, en 25% de mujeres y 21% de varones y en depósitos de hierro em 28% de mujeres y 18% de varones. La deficiencia de los depósitos de hierro en ambos sexos es el dato de mayor interés. Los resultados confirman que la población estudiada constituye un grupo de riesgo. La detección temprana de la deficiencia de hierro contribuirá a un mejor desarrollo físico e intelectual de los adolescente.

Effects of the chronic malnutrition on the transferrin receptors in patients with nutritional anemia

Se ha postulado que el aporte de hierro a las células usuarias se halla bajo un control dependiente del tamaño de la fracción intracelular libre del metal, cuyos cambios se reflejarían en mensajes a la expresión de los receptores séricos o de membrana para ajustar la oferta a la demanda. La posibilidad de que los receptores de membrana pudieran estar afectados por la malnutrición calórico-proteica se exploró en estudios a través de los cambios de la capacidad de los reticulocitos circulantes de ratón normal para incorporar hierro in vitor, observando el diferente comportamiento ocasionado por la incubación de las células con suero humano de dadores normales y de pacientes de anemia nutricional. Los resultados muestran una significativa caída de dicha capacidad cuando se utilizó suero de pacientes afectados de anemia nutricional. Se discute el probable mecanismo responsable de dicha diferencia.

Urinary elimination of erythropoietin in patients under treatment with cytostatics drugs

La reducción de la masa de hemoglobina (Hb) que ocurre en las anemias aumenta la producción de eritropoyetina (EPO) en una proporción conmensurada con el nivel de estímulo eritropoyético necesario para reponer la normalidad de la dimensión de la masa del pigmento transportador de oxigeno. Las anemias hipoplásticas congénitas (AHC) muestran niveles de Epo plasmática substancialmente mayores que las que se comprueban en anemias en las que no existe esa alteración medular. En este estudio hemos medido los niveles de Epo eliminada por orina (EpoU) en pacientes bajo tratamiento con drogas citostáticas (DC). Simultáneamente se determinaron otros parámetros hemáticos utilizados corrientemente como indicadores de la actividad medular. Nuestras observaciones sugieren que existen otros factores involucrados en la produccion de Epo además de la hipoxia tisular, los que estarían probablemente relacionados a la celularidad medular.

The nucleus of the optic tract of the opossum

This paper reviews anatomical and electrophysiological data on the nucleus of the optic tract (NOT) of the opossum, a nucleus in the afferent branch of the horizontal optokinetic reflex. It is proposed that subcortical routes are essential for responses from the two eyes: a direct retinal projection from the contralateral eye and a commissural pathway between the two NOTs for the ipsolateral eye. In the latter case there's evidence that the commisural axons have a relay on inhibitory neurones. This circuit accounts for the differences in response pattern under monocular condition: temporo-nasal motion of the visual stimulus elicits excitation in the contralateral NOT, resulting in inhibition of the ipsolateral nucleus, while naso-temporal motion promotes inhibition in the contralateral nucleus, releasing the ipsolateral nucleus from the commissural input.

Pattherns of cytochrome oxidase activity in the visual cortex of a South American opossum

The normal pattern of cytochrome oxidase (CO) activity in the posterior cortical areas of the South American opossum (Didelphis marsupialis aurita) was assessed both in horizontal section of flattened cortices and in transversal cortical sextions. the tangential distribution of CO activity was uniformly high in the strate cortex. In the peristriate region alternating bands of dense and weak staining occupied all the cortical layers with the exception of layer I. This observation suggests the existence of a functional segregation of visual processing in the peristriate cortex of the opossum similar to that present in phylogenetically more recent groups

Evidence for recrossing of the pathway from the retina to the ipsilateral nucleus of the optic tract

Single-unit recordings of the nucleous of the optic tract (NOT) under visual stimulation were performed in 5 opossums. Most of the units were directionally selective. Receptive fields for the contralateral eye lie mainly in the contralateral field while those for the ipsilateral eye were mainly in the ipsilateral field. As the nasal does not project ipsilaterally, recrossing must occur in the pathway from the retina to the ipsilateral NOT. Possible sites for this recrossing are discussed

Horizontal optokinetic reflex in the opussum Didelphis marsupialis aurita

Electro-oculographic recordings were performed in 10 opossums. The optokinetic reflex was elicited by projecting a random dot stimulus on a cylindrical screen moving horizontally from left to right or right to left at various constant speeds. Binocular stimulation yelded the same response as the temporal to nasal monocular condition. The nasal to temporal monocular response was always less than to the opposite direction: 50% at 3 degrees/s and 15% at 18 degress/s. These results are discussed in a comparative context