ApoB100/LDLR-/- hypercholesterolaemic mice as a model for mild cognitive impairment and neuronal damage.

Recent clinical findings support the notion that the progressive deterioration of cholesterol homeostasis is a central player in Alzheimer's disease (AD). Epidemiological studies suggest that high midlife plasma total cholesterol levels are associated with an increased risk of AD. This paper reports the plasma cholesterol concentrations, cognitive performance, locomotor activity and neuropathological signs in a murine model (transgenic mice expressing apoB100 but knockout for the LDL receptor [LDLR]) of human familial hypercholesterolaemia (FH). From birth, these animals have markedly elevated LDL-cholesterol and apolipoprotein B100 (apoB100) levels. These transgenic mice were confirmed to have higher plasma cholesterol concentrations than wild-type mice, an effect potentiated by aging. Further, 3-month-old transgenic mice showed cholesterol (total and fractions) concentrations considerably higher than those of 18-month-old wild-type mice. The hypercholesterolaemia of the transgenic mice was associated with a clear locomotor deficit (as determined by rotarod, grip strength and open field testing) and impairment of the episodic-like memory (determined by the integrated memory test). This decline in locomotor activity and cognitive status was associated with neuritic dystrophy and/or the disorganization of the neuronal microtubule network, plus an increase in astrogliosis and lipid peroxidation in the brain regions associated with AD, such as the motor and lateral entorhinal cortex, the amygdaloid basal nucleus, and the hippocampus. Aortic atherosclerotic lesions were positively correlated with age, although potentiated by the transgenic genotype, while cerebral ß-amyloidosis was positively correlated with genetic background rather than with age. These findings confirm hypercholesterolaemia as a key biomarker for monitoring mild cognitive impairment, and shows these transgenic mice can be used as a model for cognitive and psycho-motor decline.

Prevalencia de pterigio y exploración de posibles factores de riesgo asociados, en dos poblaciones con altitudes diferentes / Prevalence of pterygium and possible risk factors

El objetivo de este estudio fué establecer la prevalencia del pterigio en dos poblaciones colombianas ubicadas en altitudes diferentes y comparar varios factores de riesgo que han sido poco estudiados en el pais. Es un estudio descriptivo que analiza la consulta oftalmológica durante 6 meses en el ISS de Bogotá y Barranquilla entre Abril 1 y Octubre 30 de 1993. La consulta fué de 2169 paciente en Barranquilla (0 metros), de los cuales 116 (5.34 por ciento) tenían pterigio y en Bogotá (2360 metros sobre el mar) fué de 3681, de los cuales 73 (1.98 por ciento) tenían pterigio. Esta diferencia fue estadísticamente significativa (p<0.0003). En los dispensarios del ISS de las dos ciudades se utilizó un formato de historia clínica para recolección de datos y una hoja-tabla para calcular la prevalencia. Usamos el mismo formato el análisis de los factores de riesgo con los pacientes de control. El análisis estadístico fue realizado con el programa SPSS (V.5.01) utilizando regresión logística para los factores de riesgo y ji-cuadrado para la prevalencia. Encontrando relación de la actividad y la presencia de pterigio con variables como antecedentes familiares de pterigio, exposición solar, procedencia rural. Destacando que no hallando relación con alergias ni con el uso de gafas