Occupational Exposure to Coal, Genotoxicity, and Cancer Risk

Coal is a heterogeneous mixture containing large quantities of organic and inorganic matter, including carbon, hydrogen, oxygen, sulfur, nitrogen, and organometallic forms. The presence of mineral matter in coal may result in a number of environmental and human health problems related to its mining, preparation, and combustion. During coal mining activities, large quantities of coal dust, ashes, polycyclic aromatic hydrocarbons (PAHs), and heavy metals are released into the environment, forming a complex mixture. This mixture becomes one of the most important occupational risks for the health and safety of workers due to its synergistic, additive, and enhancing effects. Once inside the organism, this cocktail-like mixture can interact with cellular mechanisms related to the production of reactive oxygen species (ROS) and can cause damage in important macromolecules such as DNA, lipids, and proteins. In this review, human populations exposed to coal and coal burning were analyzed. Data from different studies were evaluated in relation to the effect of complex mixture exposure on DNA damage and mechanisms, and the background factors, such as gender, age, or smoking habit. The high temperatures that occur in combustion processes affect the characteristics of the resulting particles. The coal fly ash is released by combustion and its composition varies depending on the coal type and the method of collection used such as electrostatic precipitators. Compounds such as PAHs once activated by the organisms have been shown to have mutagenic and carcinogenic activity due to its ability to form adducts with purines. Moreover, metals that commonly are evaporated during the cooling process increase its toxicity. The particles when inhaled can pass from the alveoli into the bloodstream and affect extrapulmonary organs. Several studies have described the inflammatory cascade that triggers exposure to coal and coal fly ash particles; they have a complex composition capable of generating a persistent inflammatory process, resulting in diseases widely described as emphysema, bronchitis, pneumoconiosis, asthma, and cancer. Several human biomonitoring studies have been conducted evaluating the inflammatory process and the release of cytokines, polymorphisms involved in detoxification mechanisms, different biomarkers associated with occupational exposure, DNA damage, and the influence of oxidative stress in disease development. The relationship between chronic exposure to coal and coal ash particles and cancer is still widely debated. This review gave us a broad assessment about the associated mechanisms between cancer and exposure to coal and different findings around the world

(TTTA)n polymorphism of CYP19 (aromatase gene) in Euro-and Afro-Brazilians

We investigated the polymorphic tetranucleotide repeat (TTTA)n located in the fourth intron of the CYP19 gene in two Brazilian populations. The frequencies of the five common alleles (A) in Euro- and Afro-Brazilians were, respectively: seven repeats (A5), 0.586 and 0.80; eight repeats (A4), 0.092 and 0.06; nine repeats (A3), 0.014 and 0.01; eleven repeats (A2), 0.284 and 0.09; twelve repeats (A1), 0.021 and 0.04. In addition, one Euro-Brazilian individual had a rare allele with 13 repeats. The allelic frequencies in Euro- and Afro-Brazilians differed statistically (p < 10-3).The two samples were found to be in Hardy-Weinberg equilibrium (p = 0,828 and p = 0,995)

Estudo do gene CYP19 (aromatase) em caucasóides e pacientes que desenvolveram câncer de mama na população de Porto Alegre

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Estudo do gene CYP19 (aromatase) em caucasóides e pacientes que desenvolveram câncer de mama na população de Porto Alegre

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La correspondencia de Valencia : diario de noticias : eco imparcial de la opinión y de la prensa: Año XXXII Número 10701 - 1909 Marzo 29

Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200

(TTTA)n polymorphism of CYP19 (aromatase gene) in Euro-and Afro-Brazilians

We investigated the polymorphic tetranucleotide repeat (TTTA)n located in the fourth intron of the CYP19 gene in two Brazilian populations. The frequencies of the five common alleles (A) in Euro- and Afro-Brazilians were, respectively: seven repeats (A5), 0.586 and 0.80; eight repeats (A4), 0.092 and 0.06; nine repeats (A3), 0.014 and 0.01; eleven repeats (A2), 0.284 and 0.09; twelve repeats (A1), 0.021 and 0.04. In addition, one Euro-Brazilian individual had a rare allele with 13 repeats. The allelic frequencies in Euro- and Afro-Brazilians differed statistically (p < 10-3).The two samples were found to be in Hardy-Weinberg equilibrium (p = 0,828 and p = 0,995)

Environmental and Genetic Aspects on Leukemia Development

A etiologia da leucemia aguda (LA) pode ser explicada pela combinação de fatores genéticos e ambientais. Como exemplo das influências genéticas pode-se citar polimorfismos de genes de metabolização/detoxificação e, como de agente ambiental, a exposição ocupacional e por lazer. Tem sido descrito que leucemias infantis poderiam ter a iniciação ocorrendo in utero devido à exposição parental pré-ou durante a gestação. Este trabalho tem por objetivo analisar os polimorfismos dos genes GSTM1 e GSTT1 em relação à suscetibilidade de desenvolvimento de LA e a relação com alguns fatores ambientais. O DNA genômico de um banco de 87 pacientes foi analisado pela técnica de PCR multiplex. Também foram coletados dados de 24 famílias (pacientes pai e/ou mãe) e aplicado questionário sobre exposição. Foi detectado aumento significativo da freqüência do genótipo GSTT1 nulo quando comparado com uma população controle (40% X 21%) (P=0.005). A freqüência do genótipo nulo para GSTM1 nos pacientes não apresentou diferença significativa com relação aos controles (50% X 50%). Foi detectada uma prevalência alta de pais que relatam exposição a tintas e solventes no período de pré-concepção, podendo este ser um fator importante na origem da doença.The causes of acute leukemia (AL) are likely to involve an interaction between genetic susceptibility and environment. Polymorphisms in genes coding metabolizing/detoxification enzymes are responsible for this susceptibility. Environmental exposure (occupational or recreational) may also be involved with the etiology of leukemia. Some studies have described that infant leukemia may have the initiation period during in utero development and this may be caused by the parental pre or during the pregnancy period. The aim of this study was to analyze polymorphisms of GSTM1 and GSTT1 genes in order to verify if they have a role in genetic susceptibility to AL and correlate with some environmental aspects. Genomic DNA from 87 patients was analyzed by a multiplex PCR methodology. Material from twenty four families (the patient, the mother and/or the father) were also analyzed and a questionnaire about environmental aspects was applied. Significant increase in the prevalence of GSTT1 null genotype was detected in the patient group comparing to controls (40% X 21%) (P=0.005). No difference was found in the prevalence of GSTM1 null genotype between AL patients and controls (50% X 50%). We detected higher prevalence of occupational exposure to solvents among the fathers, being this an important aspect on leukemia development

Polimorfismos dos genes GSTP1, GSTM1, GSTT1 na população de Porto Alegre

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