RESUMEN
It is recognized that the amount of natural dilution available can make a significant difference in the exposure and risk assessment of chemicals that emanate from wastewater treatment plants (WWTPs). However, data availability is a common limiting factor in exposure assessments for emerging markets. In the present study, we used a novel approach to derive dilution factors for the receiving waters within 5 km of wastewater discharge points in Mexico by combining locally measured river volumes, ecoregion categorization, data on WWTP capacity, and global river network models. Distributions of wastewater effluent into receiving stream dilution factors were developed for the entire country and organized by ecoregion type to explore spatial differences. The distribution of dilution factors in Mexico ranged from >1000 in tropical and temperate ecoregions to 1 in desert ecoregions. To demonstrate its utility, dilution factors were used to develop a probabilistic model to explore the potential ecological risks of the high-volume surfactant linear alkylbenzene sulfonate (LAS), commonly used in down-the-drain cleaning products. The predicted LAS river exposure values were below the predicted no-effect concentration in all regions. The methodology developed for Mexico can be used to derive refined exposure assessments in other countries with emerging markets throughout the world, resulting in more realistic risk assessments. Environ Toxicol Chem 2018;37:2475-2486. © 2018 SETAC.
Asunto(s)
Ácidos Alcanesulfónicos/análisis , Monitoreo del Ambiente/métodos , Ríos/química , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Países en Desarrollo , México , Medición de Riesgo , Tensoactivos/análisisRESUMEN
In Taiwan, oral cancer is the fourth leading cause of male cancer mortality, and is still increasing. The Basiodiomycete, Agaricus brasiliensis Murill (ABM) is a dietary mushroom and has been known for its immuneenhancing, antitumor, antioxidation, antiviral and antimutagenesis functions. However, the exact anticancer mechanisms of ABM on human oral cancer cells are still unclear. In the present study, we investigated the effects of 50% ethanol crude extracts and hot water extracts of ABM on oral cancer CAL 27 cells. We observed that 0.9 mg/ml and 0.7 mg/ml of ABM 50% ethanol crude extracts and hot water, respectively, caused morphological changes and significantly reduced cell viability after 48-h treatment. The results showed that both extracts of ABM inhibited cell proliferation, increased the Ca(2+) release, reduced the mitochondria membrane potential (ΔΨm), and caused cell cycle arrest in the G(0)/G(1) phase, which contributed to apoptosis. Additionally, ABM induced DNA fragmentation, a characteristic of apoptosis and the expressions of apoptosis-related proteins, including apoptosis-inducing factor, cytochrome c, and caspase-3, were increased. Overall, we demonstrated that 50% ethanol crude extract and hot water extracts of ABM were able to induce apoptotic cell death in CAL 27 cells via the release of cytochrome c from mitochondria into the cytoplasm and activation of caspase-3 in vitro.
Asunto(s)
Agaricus/química , Apoptosis/efectos de los fármacos , Mezclas Complejas/farmacología , Mitocondrias/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Caspasa 3/metabolismo , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Citocromos c/metabolismo , Fragmentación del ADN/efectos de los fármacos , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/metabolismo , Neoplasias de la Boca/patologíaRESUMEN
OBJECTIVE: To identify an association between involvement in bullying and problems in school. STUDY DESIGN: This was a cross-sectional study of 5391 students in grades 7, 9, and 11 in an urban public school district. The main outcome measure was involvement in bullying. Secondary outcomes included attendance, grade point average, psychosocial distress, and perceived acceptability of carrying guns to school. RESULTS: Of the 5391 children surveyed, 26% were involved in bullying either as victim, bully, or both (bully-victim). All 3 groups were significantly more likely than bystanders to feel unsafe at school and sad most days. Victims and bully-victims were more likely to say they are "no good." Victims were more likely to feel that they "do not belong" in their school. The odds of being a victim (vs a bystander) were 10% lower for every 1 point increase in grade point average. Bully-victims were more likely to say that it is "not wrong" to take a gun to school. CONCLUSIONS: Associations between involvement in bullying and academic achievement, psychological distress, and the belief that it is not wrong to take a gun to school reinforce the notion that school environment is interrelated with mental health and school success.