Physiological and histological effects of cadmium, lead, and combined on Artemia franciscana.

This study analyzed the effects of cadmium (Cd) and lead (Pb) on growth, sexual couples, and histological structures of Artemia franciscana exposed to individual concentrations of these metals and combined. No histological effects were observed at tissue level in digestive, respiratory, nervous, and reproductive systems (i.e., necrosis, loss of regular structure) in individual and mixed applications on A. franciscana for 20 days of exposure. No significant differences (p > 0.05) were determined in final size and growth rate among the organisms exposed to Cd and those of control. For Pb, only the final size (3.59 ± 0.59 mm) of organisms exposed to the highest concentration was significantly lower (p < 0.05) than those of the control (4.53 ± 0.34 mm) group, whereas for the combined experiment, no significant differences (p > 0.05) were observed in final size and growth rate. At all Cd concentrations, mean sexual couples were significantly lower (p < 0.05) than those of the control, as well as for Pb. For the combined experiment (8 µg/L of Cd + 8 µg/L of Pb), sexual couples were not observed, indicating synergism and negative reproduction effects. The results showed that Cd and Pb aquatic environmental regulations (as the Criterion of Continuous Concentration) proposed by the US Environmental Protection Agency (EPA) should include their interactions with other metals.

Metals and oxidative stress in aquatic decapod crustaceans: A review with special reference to shrimp and crabs.

The objective of this review is to synthetize knowledge of the relationship between metals and oxidative stress in aquatic crustaceans (mainly shrimp and crabs) to analyze antioxidant responses when organisms are exposed to metals because the direct metal binding to the active site of enzymes inactivates most of the antioxidant systems. This study reviewed over 150 works, which evidenced that: (i) antioxidant defense strategies used by aquatic decapod crustaceans vary among species; (ii) antioxidant enzymes could be induced or inhibited by metals depending on species, concentration, and exposure time; and (iii) some antioxidant enzymes, as superoxide dismutase increase their activity in low metal levels and time exposures, but their activities are inhibited with higher metal concentrations and exposure time.

[Programa de detección del alelo APOE-E4 en adultos mayores mexicanos con deterioro cognitivo].

INTRODUCTION: In Mexico, the prevalence of neurocognitive disorders (NCDs) has increased in parallel with the increase in life expectancy. The E4 allele of the gene that encodes apolipoprotein E (APOE) is the main genetic risk factor for cognitive impairment. OBJECTIVE: To replicate the association of APOE-E4 allele with neurocognitive impairment in a Mexican population, as well as to implement a genetic risk-detection program with the APOE-E4 allele. METHOD: A program was structured for the detection of APOE-E4 allele risk in different recruiting centers from the central zone of the Mexican Republic, with three stages: recruitment and selection of candidates for the detection of the risk-allele, genetic risk analysis and delivery of results. RESULTS: In the genetic-association study to replicate the association with neurocognitive disorders by means of multivariate logistic models, the APOE-E4 allele increased the risk for cognitive impairment in the Mexican populations by approximately 6 % (OR: 5.83, p = 0.0025). In addition, 367 genetic risk results were delivered. CONCLUSIONS: The present program is the first one to be implemented in Mexico with the purpose to inform on a genetic risk factor for neurocognitive disorders in several centers of the country.

INTRODUCCIÓN: En México, la prevalencia de los trastornos neurocognitivos (TNC) han aumentado a la par del incremento en la esperanza de vida. El alelo E4 del gen que codifica la apolipoproteína E (APOE) es el principal factor de riesgo genético para deterioro neurocognitivo. OBJETIVO: Reproducir la asociación en población mexicana entre APOE-E4 y el deterioro neurocognitivo, así como implementar un programa de detección de riesgo genético con el alelo APOE-E4. MÉTODO: Se estructuró un programa de detección de riesgo basado en APO-EA en diferentes centros de reclutamiento en la zona centro de la República Mexicana, con tres etapas: reclutamiento y selección de los candidatos para la detección del alelo de riesgo, análisis del riesgo genético y entrega del resultado. RESULTADOS: El análisis de asociación genética para replicar la asociación con trastornos neurocognitivos mediante modelos logísticos multivariados mostró que el alelo E4 de APOE incrementó aproximadamente 6 % el riesgo en población mexicana (RM = 5.83, p = 0.0025). Se entregaron 367 resultados de riesgo genético. CONCLUSIONES: El presente programa es el primero en México implementado para dar a conocer un factor de riesgo genético para trastornos neurocognitivos en varios centros del país.