Effects of early and late lesion of orbital frontal cortex on visual processing of faces in rhesus macaques (Macaca mulatta)

Many mental disorders disrupt social skills, yet few studies have examined how the brain processes social information. Functional neuroimaging, neuroconnectivity and electrophysiological studies suggest that orbital frontal cortex plays important roles in social cognition, including the analysis of information from faces, which are important cues in social interactions. Studies in humans and non-human primates show that damage to orbital frontal cortex produces social behavior impairments, including abnormal aggression, but these studies have failed to determine whether damage to this area impairs face processing. In addition, it is not known whether damage early in life is more detrimental than damage in adulthood. This study examined whether orbital frontal cortex is necessary for the discrimination of face identity and facial expressions, and for appropriate behavioral responses to aggressive (threatening) facial expressions. Rhesus monkeys (Macaca mulatta) received selective lesions of orbital frontal cortex as newborns or adults. As adults, these animals were compared with sham-operated controls on their ability to discriminate between faces of individual monkeys and between different facial expressions of emotion. A passive visual paired-comparison task with standardized rhesus monkey face stimuli was designed and used to assess discrimination. In addition, looking behavior toward aggressive expressions was assessed and compared with that of normal control animals. The results showed that lesion of orbital frontal cortex (1) may impair discrimination between faces of individual monkeys, (2) does not impair facial expression discrimination, and (3) changes the amount of time spent looking at aggressive (threatening) facial expressions depending on the context. The effects of early and late lesions did not differ. Thus, orbital frontal cortex appears to be part of the neural circuitry for recognizing individuals and for modulating the response to aggression in faces, and the plasticity of the immature brain does not allow for recovery of these functions when the damage occurs early in life. This study opens new avenues for the assessment of rhesus monkey face processing and the neural basis of social cognition, and allows a better understanding of the nature of the neuropathology in patients with mental disorders that disrupt social behavior, such as autism. ^

Fundamentos biológicos para el uso de la mucosa oral como vía de aplicación de métodos inmunoterápicos

El transporte de medicamentos a través de la mucosa oral ha sido objeto de particular atención, especialmente en las ultimas dos décadas. Entre las distintas regiones de la mucosa oral, la mucosa sublingual es el sitio primario utilizado para la administración de diferentes sustancias incluidos algunos tipos de antígenos. La estructura histológica de esta área muestra la existencia de numerosas células inmunocompetentes capaces de activar el sistema inmunológico. Previo a la descripción de las diferentes rutas de absorción de fármacos y experiencias sobre permeabilidad de la región sublingual, se realiza una breve reseña de la histología y anatomía del área sublingual. En este trabajo también se tratan las ventajas y desventajas de la vía sublingual y el potencial aprovechamiento de la inmunoterapia sublingual para el tratamiento de patologías sistémicas y orales.

Lesiones estomatológicas del VPH genotipo 16 en la pre-adolescencia

El virus del Papiloma Humano infecta de manera selectiva al epitelio de la piel y las mucosas. Cuando se producen las infecciones, éstas pueden ser asintomáticas, provocando lesiones de tipos verrugosos o asociados a diversas neoplasias, benignos o malignos del tracto respiratorio superior y la cavidad bucal principalmente. Se presenta el caso de una niña con lesiones orales producidas por el VPH. Las lesiones se manifiestan clínicamente: elevadas, pediculadas y de superficie papilar; otras son planas y difusas sobre una base sésil.

Stomach content of ringed seals (Pusa hispida) obtained from the Northeast Greenland area

The diet of ringed seals (Pusa hispida) from coastal and offshore areas of Northeast Greenland was determined by identifying, to the lowest taxonomic limit possible, all hard-part contents from the gastrointestinal tract of 51 seals sampled (2002-2004) in spring (April to June, N = 35) and autumn (September to October, N = 16). The autumn diet was characterized by high numbers of Parathemisto libellula, and the spring diet was comprised primarily of polar cod (Boreogadus saida), with few invertebrates consumed. The coastal seal diet samples had a diverse fish prey composition (during both the spring and autumn), whereas the open water seals had eaten mostly crustaceans with P. libellula being most abundant. The sample sizes from the various locations and seasons were not large enough to explore age-class effects on diet in addition. Similar to earlier studies, this study suggests that the ringed seal is a generalist that exploits prey based on availability, with a few key species dominating the diet in an area at least on a seasonal basis.

Queilitis actínica tratada con imiquimod 5%

Los inmunomoduladores tópicos han demostrado utilidad en las enfermedades orales inflamatorias resistentes a corticoesteroides tópicos, en enfermedades sistémicas con mucosa oral primeramente comprometida y en lesiones severas que involucren la mucosa oral. La queilitis actínica es una lesión potencialmente maligna, con riesgo de progresar a Carcinoma espinocelular, por ello es necesario su tratamiento temprano.