Aromatase and estrogen receptor alpha mRNA expression as prognostic biomarkers in patients with astrocytomas.

Estrogens are oncogenic hormones at a high level in breast, prostate, endometrial and lung cancer. Estrogens are synthesized by aromatase which has been used as a biomarker both in breast and lung cancer. Estrogen biological activities are executed by their classic receptors (ERα and ERß). ERα has been described as a cancer promoter and ERß, as a possible tumor suppressor. Both receptors are present at low levels in primary multiforme glioblastoma (GBM). The GBM frequency is 50 % higher in men than in women. The GBM patient survival period ranges from 7 to 18 months. The purpose of this pilot study was to evaluate aromatase and estrogen receptor expression, as well as 17ß-estradiol concentration in astrocytoma patients biopsies to obtain a prognosis biomarker for these patients. We analyzed 36 biopsies of astrocytoma patients with a different grade (I-IV) of malignity. Aromatase and estrogen receptor mRNA expression were analyzed by semiquantitative RT-PCR, and the E2 levels, by ELISA. E2 concentration was higher in GBM, compared to grade II or III astrocytomas. The number of cells immunoreactive to aromatase and estrogen receptors decreased as the grade of tumor malignity increased. Aromatase mRNA expression was present in all biopsies, regardless of malignity grade or patient age or gender. The highest expression of aromatase mRNA in GBM patients was associated to the worst survival prognostic (6.28 months). In contrast lowest expression of ERα mRNA in astrocytoma patients had a worst prognosis. In conclusion, aromatase and ERα expression could be used as prognosis biomarkers for astrocytoma patients.

Estudio del sueño su historia / History of the study of sleep

El conocimiento de los mecanismos fisiológicos del sueño y de su patología ha tenido un gran desarrollo a par de la segunda mitad del siglo XX; sin embargo, existen documentos que desde el siglo XVII marcan el inicio de I electrofisiología. La técnica actual para el estudio del sueño es la polisomnografía que consiste en una serie de estudios electrofisiológicos realizados de manera simultánea; a partir de esta técnica es posible observar cambios en el funcionamiento del organismo ocurren mientras dormimos y permiten establecer con precisión la presencia de distintas etapas de sueño, así como los factores subyacentes a las distintas patologías del dormir. La polisomnografía se ha desarrollado a partir de la electrofisiología, de tal manera que es importante conocer la, evolución de ambas disciplinas para lograr una mejor comprensión del estudio actual de la medicina del sueño. En la presente revisión se hace un análisis de lo hechos más relevantes que han determinado el avance del conocimiento del sueño tanto desde el punto de vista básico como clínico.