Abordaje mediante tres cavidades de un quiste dentígero de gran tamaño: a propósito de un caso / Approach with three cavities of a large dentigerous cyst: a case report

El quiste dentígero se considera un quiste odontogénico del desarrollo que está asociado a la corona de un diente no erupcionado. Suele ser asintomático y carecer de clínica asociada por lo que frecuentemente se trata de un hallazgo casual. Sin embargo puede haber situaciones en los que el quiste afecte a estructuras próximas y/o alcance gran tamaño. Se presenta un caso de un paciente de 65 años que acude derivado por su odontólogo general al constatar la presencia de una lesión radiotransparente de gran tamaño en el cuarto cuadrante. Se realizó un abordaje mediante tres cavidades de la lesión para su completa remoción, así como del cordal incluido asociado a la misma. Por último se colocó una mini placa como refuerzo

The dentigerous cyst is considered an odontogenic developmental cyst that is associated with the crown of a non-erupted tooth. It is usually asymptomatic and has no associated clinic, so it is usually a casual fi nding. However, it can affect nearby structures and / or reach large size. A case of a 65-year-old patient is presented who is referred by his general dentist to verify the presence of a large radiolucent lesion in the fourth quadrant. An approach was made using 3 cavities of the lesion for its complete removal, as well as the included wisdom tooth associated with it. Finally, a mini fi xing plate was placed as reinforcement

The Alteration of Emotion Regulation Precedes the Deficits in Interval Timing in the BACHD Rat Model for Huntington Disease.

Huntington disease (HD) is an autosomal dominantly inherited, progressive neurodegenerative disorder which is accompanied by executive dysfunctions and emotional alteration. The aim of the present study was to assess the impact of emotion/stress on on-going highly demanding cognitive tasks, i.e., temporal processing, as a function of age in BACHD rats (a "full length" model of HD). Middle-aged (4-6 months) and old (10-12 months) rats were first trained on a 2 vs. 8-s temporal discrimination task, and then exposed to a series of bisection tests under normal and stressful (10 mild unpredictable foot-shocks) conditions. The animals were then trained on a peak interval task, in which reinforced fixed-interval (FI) 30-s trials were randomly intermixed with non-reinforced probe trials. After training, the effect of stress upon time perception was again assessed. Sensitivity to foot-shocks was also assessed independently. The results show effects of both age and genotype, with largely greater effects in old BACHD animals. The older BACHD animals had impaired learning in both tasks, but reached equivalent levels of performance as WT animals at the end of training in the temporal discrimination task, while remaining impaired in the peak interval task. Whereas sensitivity to foot-shock did not differ between BACHD and WT rats, delivery of foot-shocks during the test sessions had a disruptive impact on temporal behavior in WT animals, an effect which increased with age. In contrast, BACHD rats, independent of age, did not show any significant disruption under stress. In conclusion, BACHD rats showed a disruption in temporal learning in late symptomatic animals. Age-related modification in stress-induced impairment of temporal control of behavior was also observed, an effect which was greatly reduced in BACHD animals, thus confirming previous results suggesting reduced emotional reactivity in HD animals. The results suggest a staggered onset in cognitive and emotional alterations in HD, with emotional alteration being the earliest, possibly related to different time courses of degeneration in cortico-striatal and amygdala circuits.

Interfacial interactions between Skeletonema costatum extracellular organic matter and metal oxides: Implications for ceramic membrane filtration.

In the current study, the interfacial interactions between the high molecular weight (HMW) compounds of Skeletonema costatum (SKC) extracellular organic matter (EOM) and ZrO2 or Al2O3, were investigated by atomic force microscopy (AFM). HMW SKC-EOM was rigorously characterized and described as a hydrophilic organic compound mainly comprised of polysaccharide-like structures. Lipids and proteins were also observed, although in lower abundance. HMW SKC-EOM displayed attractive forces during approaching (i.e., leading to jump-to-contact events) and adhesion forces during retracting regime to both metal oxides at all solution conditions tested, where electrostatics and hydrogen bonding were suggested as dominant interacting mechanisms. However, the magnitude of these forces was significantly higher on ZrO2 surfaces, irrespective of cation type (Na+ or Ca2+) or concentration. Interestingly, while HMW SKC-EOM interacting forces to Al2O3 were practically insensitive to solution chemistry, the interactions between ZrO2 and HMW SKC-EOM increased with increasing cation concentration in solution. The structure, and lower charge, hydrophilicity, and density of hydroxyl groups on ZrO2 surface would play a key role on favoring zirconia associations with HMW SKC-EOM. The current results contribute to advance our fundamental understanding of Algogenic Organic Matter (AOM) interfacial interactions with metal oxides (i.e., AOM membrane fouling), and would highly assist in the proper selection of membrane material during episodic algal blooms.

Impaired Decision Making and Loss of Inhibitory-Control in a Rat Model of Huntington Disease.

Cognitive deficits associated with Huntington disease (HD) are generally dominated by executive function disorders often associated with disinhibition and impulsivity/compulsivity. Few studies have directly examined symptoms and consequences of behavioral disinhibition in HD and its relation with decision-making. To assess the different forms of impulsivity in a transgenic model of HD (tgHD rats), two tasks assessing cognitive/choice impulsivity were used: risky decision-making with a rat gambling task (RGT) and intertemporal choices with a delay discounting task (DD). To assess waiting or action impulsivity the differential reinforcement of low rate of responding task (DRL) was used. In parallel, the volume as well as cellular activity of the amygdala was analyzed. In contrast to WT rats, 15 months old tgHD rats exhibited a poor efficiency in the RGT task with difficulties to choose advantageous options, a steep DD curve as delays increased in the DD task and a high rate of premature and bursts responses in the DRL task. tgHD rats also demonstrated a concomitant and correlated presence of both action and cognitive/choice impulsivity in contrast to wild type (WT) animals. Moreover, a reduced volume associated with an increased basal cellular activity of the central nucleus of amygdala indicated a dysfunctional amygdala in tgHD rats, which could underlie inhibitory dyscontrol. In conclusion, tgHD rats are a good model for impulsivity disorder that could be used more widely to identify potential pharmacotherapies to treat these invasive symptoms in HD.

In vitro particle image velocity measurements in a model root canal: flow around a polymer rotary finishing file.

INTRODUCTION: Root canal irrigation is vital to thorough debridement and disinfection, but the mechanisms that contribute to its effectiveness are complex and uncertain. Traditionally, studies in this area have relied on before-and-after static comparisons to assess effectiveness, but new in situ tools are being developed to provide real-time assessments of irrigation. The aim in this work was to measure a cross section of the velocity field in the fluid flow around a polymer rotary finishing file in a model root canal. METHODS: Fluorescent microparticles were seeded into an optically accessible acrylic root canal model. A polymer rotary finishing file was activated in a static position. After laser excitation, fluorescence from the microparticles was imaged onto a frame-transfer camera. Two consecutive images were cross-correlated to provide a measurement of a projected, 2-dimensional velocity field. RESULTS: The method reveals that fluid velocities can be much higher than the velocity of the file because of the shape of the file. Furthermore, these high velocities are in the axial direction of the canal rather than only in the direct of motion of the file. CONCLUSIONS: Particle image velocimetry indicates that fluid velocities induced by the rotating file can be much larger than the speed of the file. Particle image velocimetry can provide qualitative insight and quantitative measurements that may be useful for validating computational fluid dynamic models and connecting clinical observations to physical explanations in dental research.

Comparación del conocimiento sobre tabaquismo en alumnos de 4º a±o en 2 colegios de Lima / Comparison of the knowledge on smoking in pupils of 4 º year in 2 colleges of Lima

Introducción: En el Perú, los adolescentes que fuman estßn entre el 18 y 23 por ciento, con un inicio entre 13 -15 a±os. Objetivo: Comparar los factores culturales familiares, relacionados con el tabaquismo, así como el nivel de conocimiento que tienen los escolares sobre los efectos nocivos y su predisposición a fumar. Dise±o: Encuesta de corte transversal en el campo educativo. Marco de referencia: Población de educación secundaria. Participantes: Alumnos del 4° a±o de secundaria de 2 colegios de Lima. Intervenciones: Cuestionario preestablecido y modificado explorando tabaquismo en el circulo familiar, conocimientos sobre los riesgos y complicaciones y sus perspectivas en el inicio del tabaquismo. Resultados: se objetivó una frecuencia mayor de tabaquismo entre las madres del colegio de nivel A 35 por ciento que el B 18 por ciento, e inclusive que la de los padres que fuman. El porcentaje de ni±os que piensan fumar es bajo (8 por ciento en el nivel A y 4 por ciento en el nivel B) y se evidencia la exposición a la publicidad especialmente por la televisión casi por igual en ambos grupos (77 por ciento y 75 por ciento para A y B, respectivamente) Conclusiones: Se debe realizar campa±as de prevención agresivas antes de la adolescencia temprana. La influencia de los padres en el inicio del tabaquismo es un factor muy importante a considerar, se requiere estudios de tipo comparativo y con mayor población para ver el rol que juega la madre.