Toxic effects of Arianor Ebony hair dye on human cells

To evaluate the risks of hair dye exposure, we investigated cellular and molecular effects of Arianor Ebony dye, which is a mixture of azo and anthraquinone dyes, used in the composition of the black color. Cytotoxicity, genotoxicity, and gene expression of relevant molecules of apoptotic and oxidative stress mechanisms were investigated in HepG2 cells exposed to Arianor Ebony. Results showed that the dye did not induce cytotoxicity to exposed cells at a concentration up to 50 µg/mL compared to the negative control. However, genotoxic assays indicated that the dye was able to damage the genetic material at a concentration of 25 µg/mL, with induction factor values of exposed cells two- to five-fold higher than those recorded for the negative control. Moreover, the lowest observed effect concentration was 12.5 µg/mL. For gene expression, relevant changes were observed in cytochrome c and caspase 9, which decreased in cells incubated with the dye in a dose-dependent manner when compared with the negative control. In parallel, the expression of genes for antioxidant enzymes was increased in exposed cells, suggesting the presence of metabolic routes that protect cells against the toxic effect of the dye, avoiding exacerbated cellular death. Results suggested that the dye disrupted cellular homeostasis through mitochondrial dysfunction, which may be hazardous to human health. Thus, further investigations are necessary to deeply understand the mechanisms of action of the dye, considering its toxic potential found in our ex vivo assays.

Factores que influyen en la distribución de nidos de la hormiga Argentina Linepithema humile Mayr (Hymenoptera: Formicidae), en un ecosistema precordillerano de la zona central de Chile / Factors influencing the distribution of nests of the Argentine ant Linepithema humile Mayr (hymenoptera: formicidae), in a foothills ecosystem of the central zone of Chile

The purpose of this research was to demonstrate the dependant relationship between the Argentine ant Linepithema humile Mayr, plant coverage, and human settlements. A method was designed in order to sample the presence of the Argentine ant and other ant species that may had influenced L. humile distribution, under different types of vegetation and percentages of plant coverage, taking in consideration the distance from human settlements. Eight sample stations were established. Four of these stations were found on a dwelling home and the other four were found on similar areas, but far from human settlements. Three transects were established from the center of each sampling station (Tt1, shrublike vegetation, Tt2, herblike vegetation and Tt3, no vegetation). Transects were compound by 10 m side quadrants. A negative correlation was found between nest number of L. humile and human settlement distance, therefore nests were not found at distances higher than 80 m, in all studied areas. There was a positive and significant correlation between nest number of L. humile and plant coverage percentage, regardless the type of vegetation found. The same trend was found for other ant species studied in the area. Finally, it was proved that the distribution of L. humile nests is not influenced by other ant species.

Resultados de 500 biopsias prostáticas transrectales / Results of 500 transrectal prostatic biopsies

El adenocarcinoma prostático es uno de los tumores más frecuentes y su incidencia ha aumentado. El objetivo de este trabajo es evaluar el valor del APE para la detección de un tumor prostático por medio de la biopsia transrectal y analizar la morbilidad del procedimiento. Se realizó un estudio retrospectivo de 500 biopsias transrectales en un período de 2 años. En los pacientes con APE < de 4 ng/ml, se encontró cáncer en un 12.9 por ciento, para los pacientes con APE entre 4 y 10 ng/ml hubo un 15.2 por ciento de cáncer, el grupo con valores de APE de 10 a 20 ng/ml la positividad de la biopsia fue del 30 por ciento, de un 54 por ciento para valores entre 20 y 50 ng/ml y del 88 por ciento para valores mayores. Hubo un aumento de los grados de indiferenciación (Gleason), conforme aumenta el valor del APE, este no fue estadísticamente significativo. La morbilidad de la serie fue baja (1,6 por ciento) y de fácil manejo médico. Creemos que la biopsia prostática transrectal es un método que permite la toma de muestras en forma segura y con baja morbilidad. Existe una buena correlación entre los valores del APE y el porcentaje de biopsias positivas, demostrando su sensibilidad para la detección de tumores prostáticos