RESUMO

BACKGROUND: Overweight and obesity in childhood is associated with negative physical and psychological effects. It has been proposed that obesity increase the risk for developing cognitive deficits, dementia and Alzheimer's disease and that it may be associated with marked differences in specific brain structure volumes. OBJECTIVE: The purpose of this study was a neurobiopsychological approach to examine the association between overweight and obesity, brain structure and a paediatric neuropsychological assessment in Mexican children between 6 and 8 years of age. METHODS: We investigated the relation between the body mass index (BMI), brain volumetric segmentation of subcortical gray and white matter regions obtained with magnetic resonance imaging and the Neuropsychological Assessment of Children standardized for Latin America. Thirty-three healthy Mexican children between 6 and 8 years of age, divided into normal weight (18 children) and overweight/obese (15 children) groups. RESULTS: Overweight/obese children showed reduced executive cognitive performance on neuropsychological evaluations (i.e. verbal fluidity, P = 0.03) and presented differences in brain structures related to learning and memory (reduced left hippocampal volumes, P = 0.04) and executive functions (larger white matter volumes in the left cerebellum, P = 0.04 and mid-posterior corpus callosum, P = 0.03). Additionally, we found a positive correlation between BMI and left globulus pallidus (P = 0.012, ρ = 0.43) volume and a negative correlation between BMI and neuropsychological evaluation scores (P = 0.033, ρ = -0.37). CONCLUSIONS: The findings contribute to the idea that there is a relationship between BMI, executive cognitive performance and brain structure that may underlie the causal chain that leads to obesity in adulthood.

Assuntos

RESUMO

El objetivo de este trabajo fue estudiar la maduración dentaria en jóvenes venezolanos estimada mediante el método de Demirjian y cols. Se analizaron 284 radiografías panorámicas de pacientes de ambos sexos con edades cronológicas entre 8- 20 años. Se estudio la maduración dentaria de los 7 dientes inferiores izquierdos de acuerdo a los estadios del método de Demirjian y cols. y se calculó la edad dentaria. Se obtuvieron la media y la desviación estándar de la edad cronológica (EC) y la ED, la media de la EC a la cual se observaron los diferentes estadios de maduración y diferencias de medias entre la EC y la ED calculada. Al comparar las medias de las edades cronológicas en las que se observaron los estadios de maduración dentaria, las hembras tuvieron un desarrollo más avanzado que los varones. Se evidencio que el 100% de madurez dentaria, comienza a alcanzase alrededor de lo 13-14 años en la muestra estudiada. Contrastando la media de la EC con la ED, pudo verificarse que en ambos sexos, existe una consistente subestimación de la edad a partir de los 16 años, por ello en una submuestra de los grupos 8-16 se obtuvieron las diferencias de media entre la EC y ED, y se encontró una sobrestimación de la edad, estadísticamente significativa (-0,66 ±1,14 varones; -0,40± 1,38 hembras). Los datos del presente trabajo podrían ser utilizados como referencia de la maduración dentaria de los individuos de la muestra...

The aim of the present investigation was to study the dentaria maturation of Venezuelan young estimated though Demirjian´s et al. method. Two hundred and eighty four dentaria panoramic radiographs from patients of both sexes, with chronological ages between 8-20 years, were analyzed. Dentaria maturation of the 7 left lower teeth was calculated, according to the stages proposed by Demirjian et al. and dentaria age was calculated (DA) following the method of the author. Mean values and standard deviation of the chronological age (CA) and DA, by age group, mean of the CA to which different stages of maturation were observed and mean differences between the CA and the DA, were calculated. When comparing the mean chronological ages witch the dentaria maturation stages were observed; females had more advanced development than males. It was noticed that 100% of dentaria maturity, was reached out around 13-14 years in the studied sample. Contrasting mean CA with DA, it could be confirmed that in both sexes, there is a consistent underestimation of age from 16 years, so in a subsample of 8-16 groups mean differences between the EC and ED were obtained, and found an statistically significant overestimation of age (males -0.66 ± 1.14, females -0.40 ± 1.38). The data presented here could be used as a reference for dentaria maturation of the individuals in the sample...

Assuntos

RESUMO

INTRODUCTION: Attention deficit/hyperactivity disorder (ADHD) is a common behavioral disorder found mainly in males, thus current knowledge on its clinical expression in female adults is extremely limited. AIM. To evaluate the behavioral and neural substrates associated with the performance of a short-term memory task in female ADHD adults, with and without methylphenidate exposure, with respect to a control group. SUBJECTS AND METHODS: Two groups of eight young right-handed, female, university students with ADHD and healthy controls matched by age, gender, handedness and academic level, voluntarily participated. All subjects performed twice an easy auditory short-term memory task (ADHD group without, and 90 minutes post-intake of methylphenidate 0.4 mg/kg in a counterbalanced order). The BOLD-fMRI response was used as a measure of neural activity during task performance. RESULTS: ADHD subjects showed a tendency to improve their performances under medication, showing an increased widespread functional activation, especially relevant over left frontal and cerebellar areas, in comparison with control subjects. CONCLUSIONS: Methylphenidate slightly improves short-term memory task performance in adult female ADHD subjects by modifying underlying neural functioning patterns.

Assuntos

RESUMO

The development of clinical magnetic resonance imaging in Mexico has followed a different course from that in the U.S. and Europe. The first clinical unit was installed in Mexico in the late 1980s at the very beginning of clinical applications worldwide. Since then, installations have proceeded at a sedate pace that now brings the installed total to 66 imagers. The largest fraction of these units (28, or 42%) is in Mexico City, with a broad distribution across the remaining 23 Mexican states. There is a noticeable increase of the number of units (20, or 30%) in the states bordering the U.S., while the states bordering nations to the south have no units. More than half the units (38, or 58%) are 0.5 T units, while a further 35% are 1.0 T or higher. Slower addition of units in Mexico relative to the U.S. is attributed to the higher fraction of public-funded hospitals and the inherent conservatism of such institutions when considering new technologies. Present public planning for health care development suggests that the coming decade will see more rapid installation of units to meet growing demand in Mexico for the latest medical technology. Experience over the past two decades indicates the need for more systematic training of technical and clinical personnel to implement these additions. The National University (Universidad Nacional Autónoma de México (UNAM) and the Metropolitan University (Universidad Autónoma Metropolitana (UAM) are collaborating with diverse clinical facilities to create such a program. J. Magn. Reson. Imaging 2001;13:813-817.

Assuntos

Assuntos

Assuntos