Assessment of genotoxic damage induced by exposure to binary mixtures of polycyclic aromatic hydrocarbons and three heavy metals in male mice.

INTRODUCTION: Heavy metals (HM) and polycyclic aromatic hydrocarbons (PAHs) exposition has been associated with health problems. Therefore, this research evaluated genotoxicity induced in male mice strain CD-1 exposed to benzo[a]anthracene (B[a]A) and benzo[a]pyrene (B[a]P) and their interaction with Fe, Pb, and Al. METHODS: Groups of animals were exposed intraperitoneally to HM, PAHs, and mixtures of both. Peripheral blood samples were taken from 0 to 96 h at 24 h intervals; genotoxicity was determined by micronucleus tests and comet assay. Additionally, toxicity and viability were evaluated. RESULTS: HM and PAHs individually were genotoxic. About toxicity, only Al altered polychromatic erythrocytes number and did not change leukocytes viability. Concerning mixtures, Fe + B[a]P, Fe + B[a]A, Pb + B[a]P increased genotoxicity. There were no changes with Pb + B[a]A. Finally, Al mixtures with both PAHs damage was decreased. CONCLUSIONS: Exposure to HM and PAH caused genetic damage. Fe, Al, and B[a]A, established a genotoxic potential. Every metal can interact with PAHs in different ways. Also, the micronucleus test and the comet assay demonstrated their high capacity and reliability to determine the genotoxic potential of the compounds evaluated in this work.

Occupational exposure to pesticides: DNA damage in horticulturist from Nativitas, Tlaxcala in Mexico.

Mexico is a country where agricultural activity is of great importance, but biomonitoring data are still scarce. With more intensive pesticides use per unit area/surface in horticultural productivity, there is a higher impact on environmental contamination and workers' health. Considering that exposure to various pesticide and pesticide mixtures represents an additional genotoxic risk, the appropriate characterization of exposure, confounding factors and the risk itself are very much needed. We compared genetic damage in 42 horticulturists and 46 unexposed controls (Nativitas, Tlaxcala) using alkaline comet (whole blood) and micronucleus (MN) test with nuclear abnormalities (NA) (buccal epithelial cells). Workers demonstrated significantly higher levels of damage (TI%=14.02 ± 2.49 vs. 5.37 ± 0.46; MN=10.14 ± 5.15 vs. 2.40 ± 0.20), with more than 90% of them not using protective clothing nor gloves during application. Combined DNA damage techniques and periodic monitoring together with educational programs for safe pesticide application is the best strategy to assess and prevent workers' health risks.

Nanotechnology in agriculture: a review of genotoxic studies of nanopesticides in animal cells.

Agriculture has been and still is one of the most influential primary operations in economic history worldwide. Its social, cultural, and political impact allows the progression and survival of humanity. Sustaining the supply of primary resources is crucial for the future. Therefore, the development of new technologies applied to agrochemicals is growing to obtain better food quality faster. Recently, nanotechnology has gained strength in this field in the last decade, mainly because of the presumed benefits that will carry with it compared with the current commercial presentations, like the decrease of risk in non-target organisms. The harm of pesticides is commonly associated with unwanted effects on human health, some with long-term genotoxic effects. Therefore, it would be relevant to set the existence of a risk or a benefit of the nanopesticides from a genotoxic point of view, comparing against those without this technology. Although some studies are concerned with its genotoxicity in live aquatic organisms, few focus on human in vitro models. Several studies conclude that some of them can induce oxidative stress, leading to DNA damage or cell death. However, there is still much to investigate to establish an accurate and complete assessment. In this review, we aim to give an overview of the genotoxic effect caused by nanopesticides in animal cells and a guide to the evolution of this topic, offering a base and critical review to facilitate future research.

Management of Suprachoroidal Hemorrhage during Phacoemulsification: A Comprehensive Review.

Suprachoroidal hemorrhage (SCH) is a rare and sight-threatening complication of various intraocular surgeries, including cataract surgery. Although the rate of SCH complicating cataract surgery has decreased in the era of phacoemulsification, most likely due to smaller self-sealing incisions and modern equipment, it remains a challenging complication to manage. The aim of this review is to summarize the current evidence of the pathophysiology and management of SCH complicating phaco surgery. A literature review was performed using the PubMed database searching for diagnosis, therapy, and management of SCH during phacoemulsification. The evidence available on the optimal management of this condition is low, and there is no consensus so far. An early diagnosis is thought to be essential to avoid progression to the devastating stage of expulsion of intraocular contents (expulsive hemorrhage). Sudden intraoperative anterior chamber shallowing, red reflex loss, and a significant increase in intraocular pressure are highly suspicious for this severe complication. A fundus examination and ocular ultrasound are crucial to confirm the diagnosis and, if it is confirmed, stabilize the globe immediately. The initial therapeutic approach includes aggressive topical and systemic medication focused on controlling ocular inflammation and intraocular pressure, whereas the timing and the indications of surgical intervention remain controversial.

Henle fiber layer hemorrhage as the first manifestation of factor V Leiden homozygous mutation.

PURPOSE: To report a case of a Henle fiber layer hemorrhage as the initial manifestation of Factor V Leiden disease. METHODS: Case report and literature review. RESULTS: A healthy 19-year-old patient presented with a spontaneous Henle fiber layer (HFL) hemorrhage. The genetic analysis showed a previously unknown homozygous Factor V Leiden Mutation. No specific treatment was given due to the patient's good visual acuity and favorable prognosis, but the diagnosis of a Factor V Leiden mutation enabled a correct therapeutic management to be followed by the patient. CONCLUSION: Advances in eye imaging allow to detect ocular findings that may lead to an early diagnosis and treatment. To the best of our knowledge, this is the first case of a HFL hemorrhage as the initial manifestation of Factor V Leiden disease. Further research is needed to identify the pathways linking these findings.

The microRNAs as potential biomarkers for predicting the onset of aflatoxin exposure in human beings: a review.

The identification of aflatoxins as human carcinogens has stimulated extensive research efforts, which continue to the present, to assess potential health hazards resulting from contamination of the human food supply and to minimize exposure. The use of biomarkers that are mechanistically supported by toxicological studies will be important tools for identifying stages in the progression of development of the health effects of environmental agents. miRNAs are small non-coding mRNAs that regulate post-transcriptional gene expression. Also, they are molecular markers of cellular responses to various chemical agents. Growing evidence has demonstrated that environmental chemicals can induce changes in miRNA expression. miRNAs are good biomarkers because they are well defined, chemically uniform, restricted to a manageable number of species, and stable in cells and in the circulation. miRNAs have been used as serological markers of HCC and other tumors. The expression patterns of different miRNAs can distinguish among HCC-hepatitis viruses related, HCC cirrhosis-derivate, and HCC unrelated to either of them. The main objective of this review is to find unreported miRNAs in HCC related to other causes, so that they can be used as specific molecular biomarkers in populations exposed to aflatoxins and as early markers of exposure, damage/presence of HCC. Until today specific miRNAs as markers for aflatoxins-exposure and their reliability are currently lacking. Based on their elucidated mechanisms of action, potential miRNAs that could serve as possible markers of HCC by exposure to aflatoxins are miR-27a, miR-27b, miR-122, miR-148, miR-155, miR-192, miR-214, miR-221, miR-429, and miR-500. Future validation for all of these miRNAs will be needed to assess their prognostic significance and confirm their relationship with the induction of HCC due to aflatoxin exposure.

Efectos de la contaminación del aire en células humanas de pulmón / Effects of air pollution in human lung cells

Introducción. Las PM2.5 son componentes de la atmósfera de la Ciudad de México. Contienen, entre otros compuestos, los hidrocarburos aromáticos policíclicos, que tienen efectos tóxicos conocidos. Debido a las diferencias en la composición de las PM2.5 en las diferentes zonas de la Ciudad de México, y la falta de información sobre sus efectos, el objetivo del estudio fue evaluar la cito y genotoxicidad de la fracción orgánica soluble que contienen los hidrocarburos aromáticos policíclicos, de las PM2.5 provenientes de las estaciones de monitoreo Noreste (NE), Centro (C) y Suroeste (SO) de la Ciudad de México, en cultivo de células NL-20 humanas durante 24 horas. Métodos. Se extrajo la fracción orgánica soluble de los filtros con las PM2.5 de las diferentes estaciones de monitoreo. Se cultivaron las células bronquiales humanas y, posteriormente, se realizaron los ensayos de exposición a la fracción orgánica soluble para evaluar el efecto en la viabilidad y en la inducción de genotoxicidad. Resultados. Los resultados mostraron que 0.1 μg/μl de fracción orgánica soluble de la estación Centro fue la más citotóxica, reduciendo a 52.4% y 54.2% la viabilidad celular, en las temporadas tanto de sequía como de lluvia, respectivamente. Esta fracción orgánica soluble indujo anormalidades celulares, como multinucleación y atipia nuclear. Los porcentajes contrastaron con los obtenidos de la estación NE que fueron 91.2% y 85% a la misma concentración, respectivamente (p <0.05). La concentración de 0.1 μg/μl, tanto de la estación NE como de la del C, fue genotóxica. Conclusiones. La fracción orgánica soluble de la zona Centro fue la más citotóxica, ya que es la zona con mayor concentración de automóviles que son la fuente principal de hidrocarburos aromáticos policíclicos.

Background. PM2.5 are components of the atmosphere of Mexico City and contain polycyclic aromatic hydrocarbons (PAH), which induce toxic effects. Due to different compositions of the PM2.5 in all zones of Mexico City and the lack of information about their effects, the main purpose of this study was to evaluate the cytotoxicity and genotoxicity due to soluble organic fractions (SOFs), which contains PAH isolated from the PM2.5 collected from several monitoring stations in Mexico City (northeast, downtown, and southwest) in a cell culture of human line NL-20 during a 24-h period. Methods. We extracted the soluble organic fraction of PM2.5 filters from the different monitoring stations. Human bronchial cells were cultured and subsequently assays were performed on the exposure of SOFs to evaluate the effect on the viability and induction of genotoxicity. Results. Results show that 0.1 μg/μl of SOF from the downtown station was more cytotoxic, reducing cell viability to 52.4% and 54.2% in both dry and rainy periods, respectively. Also, cellular anomalies were induced such as multinucleation and nuclear atypia. These percentages of cytotoxicity contrasted against those obtained from SOFs from the northeast area that were 91.2% and 85% at the same concentration during both dry and rainy periods, respectively (p <0.05). Only at 0.1 μg/μl SOF were the results genotoxic from the northeast and downtown (p <0.05). Conclusions. SOFs from the downtown zone were the most cytotoxic due to the high concentration of automobiles as the main sources of PAH.

Differential mutagenic response of Salmonella typhimurium to the plant-metabolized organophosphorus insecticides, phoxim and azinphos methyl.

The plant cell/microbe coincubation assay was used to analyze organophosphorus insecticide activation. Salmonella typhimurium strains TA98 and TA100 were exposed to several concentrations of the pesticides phoxim and azinphos methyl with and without TX1 cell line of Nicotiana tabacum activation. When the bacterial strains were treated directly with phoxim, mutagenic activity increased significantly. In contrast, no mutagenic activity was detected with plant activation. Azinphos methyl inhibited the growth of Salmonella strains without plant activation. The coincubation with N. tabacum increased mutagenic activity significantly. These findings and those obtained in animals demonstrated that azinphos-methyl was an indirect mutagen or pro-mutagen activated by the plant metabolism.