Papers by Marcos Felipe de Oliveira Galvão
Universidade Federal do Rio Grande do Norte, Apr 5, 2016
Environmental and Molecular Mutagenesis, 2021
We previously showed that farmers in Bolivia are exposed to many pesticides, some at elevated lev... more We previously showed that farmers in Bolivia are exposed to many pesticides, some at elevated levels, and that this was associated with increased risk of genetic damage. To improve the understanding of possible mixture effects, the cytotoxicity and genotoxicity of pesticides were studied in vitro using human liver HepG2 cells. The studied pesticides were 2,4‐D, chlorpyrifos, cypermethrin, glyphosate, methamidophos, paraquat, profenofos, and tebuconazole. Three mixtures (U1, U2, and U3) were based on profiles of urinary pesticide metabolites and one mixture on the most frequently used pesticides (S1). The results showed that paraquat and methamidophos were the most cytotoxic pesticides (EC50 ≤0.3 mM). Paraquat, chlorpyrifos, tebuconazole, and the U1, U2, and U3 mixtures, which contained a large proportion of either chlorpyrifos or tebuconazole, significantly increased intracellular ROS levels. Most pesticides activated DNA damage signaling through proteins Chk1 and H2AX. Strongest responses were elicited by paraquat, profenofos, chlorpyrifos, cypermethrin, and the S1 mixture, which contained 25% paraquat. Comet assay revealed significant increases of DNA damage in response to paraquat, cypermethrin, and U2 and S1 mixtures, which contained high levels of cypermethrin and paraquat, respectively. In summary, we showed that the tested pesticides, alone or in mixtures, in general induced oxidative stress and that most pesticides, and especially paraquat and cypermethrin, were genotoxic in HepG2 cells. We could also show that mixtures dominated by these two pesticides displayed a marked genotoxic potency, which agreed with our previous population studies.
Environment International
Whole mixture-based testing using in vitro new approach methodologies (NAMs) has been suggested t... more Whole mixture-based testing using in vitro new approach methodologies (NAMs) has been suggested to facilitate the hazard and risk assessment of complex environmental mixtures. Previous studies have shown that phosphorylation of DNA damage signaling proteins checkpoint kinase 1 (pChk1) and histone 2AX (γH2AX) are sensitive markers that can be used for estimating carcinogenicity potencies in vitro. Here, and with the aim to better validate the applicability, in vitro-based Mixture Potency Factors (MPFs) of Standard Reference Materials (SRMs) from environmental polycyclic aromatic hydrocarbon (PAH)-containing mixtures were determined and compared to published mutagenicity and tumorigenicity data. Also, genotoxicity was assessed by a flow cytometry-based micronucleus (MN) assay which showed that only benzo[a]pyrene (B[a]P) and coal tar SRM (SRM1597a) caused dose-dependent increases of MN formation, while extracts of diesel particulate matter (SRM1650b), diesel particulate extract (SRM1975), and urban dust (SRM1649b) did not. However, a dosedependent activation of DNA damage signaling was observed for all PAHs and SRMs. The results demonstrated that all SRMs were more potent than B[a]P, at B[a]P-equivalent concentrations, to induce pChk1 and γH2AX, and that western blot was more sensitive than the In-Cell Western assay in detecting their activation in response to these complex mixtures. Relative MPFs, based on dose-response modelling of pChk1 and γH2AX, ranged 113-5270 for the SRMs, indicating several orders of magnitude higher genotoxic potential than B[a]P. Moreover, these MPFs were in good agreement with potency values based on published data from Salmonella mutagenicity and in vivo carcinogenicity studies. In conclusion, these comparisons further validate the feasibility of applying in vitro NAMs, such as whole-mixture based MPFs, in cancer risk assessment of complex mixtures.
Journal of Paediatrics and Child Health
AIM This study aimed to evaluate the association of toll-like receptor (TLR) inflammatory cascade... more AIM This study aimed to evaluate the association of toll-like receptor (TLR) inflammatory cascade with the development of diabetic kidney disease (DKD) in children and adolescents with type 1 diabetes (T1D). METHODS A total of 49 T1D patients and 49 normoglycaemic (NG) subjects aged 5-20 years old were recruited. TLR2, TLR4, MYD88, NFKB, MCP1/CCL2 and IL18 mRNA expressions were measured in peripheral blood mononuclear cells by reverse transcription-quantitative polymerase chain reaction. Fasting glucose, glycated haemoglobin, serum urea, serum creatinine and urinary albumin-to-creatinine ratio (ACR) were determined. RESULTS The mRNA expressions of TLR2, TLR4, MYD88 and NFKB were significantly increased in the T1D group compared with the NG group. The mRNA expression levels of MCP1/CCL2 and IL18 were higher in 21 T1D patients (42.9%) (average of MCP1/CCL2: 6.6-fold and IL18: 5.8-fold) than in NG patients. Furthermore, ACR was increased in the T1D group compared with the NG group. CONCLUSION The increased mRNA expression of TLR2, TLR4, MYD88, NFKB, MCP1/CCL2 and IL18 favours the development of an inflammatory process that may lead to a decline in renal function and consequently DKD in children and adolescents with T1D. This suggests that these genes are early mediators of onset DKD since the beginning of the lives of the paediatric T1D patients.
Mastology
Introdução: Atualmente, precisamos selecionar adequadamente as pacientes a serem submetidas à bió... more Introdução: Atualmente, precisamos selecionar adequadamente as pacientes a serem submetidas à biópsia de linfonodo sentinela. Para isso, são imprescindíveis a avaliação da predição daquele paciente acerca do comprometimento linfonodal e a avaliação da acurácia do exame clínico. Objetivo: O presente estudo teve como objetivo avaliar o conteúdo axilar de pacientes portadoras de câncer de mama com tumores entre três e cinco centímetros submetidas ao esvaziamento axilar entre 2010 e 2013, por meio da análise de 102 prontuários. Métodos: Os dados foram categorizados segundo a avaliação clínica axilar positiva ou negativa e a avaliação anatomopatológica positiva ou negativa. Resultados: Observaram-se valor preditivo positivo do exame físico de 83,5% e preditivo negativo de 34,88%. O exame físico axilar mostrou sensibilidade de 63,6% e especificidade de 60%. A maioria das pacientes com comprometimento axilar no anatomopatológico mostrou correlação com o grau tumoral, tamanho, localização e invasão angiolinfática. Conclusão: Acredita-se que uma melhor avaliação quanto à predição do comprometimento linfonodal, levando em consideração alguns fatores clinicopatológicos de risco nas pacientes com linfonodos suspeitos, deve ser feita como auxílio no estudo pré-operatório da axila e triagem no tocante à abordagem axilar.
Most research concerning the effects of air pollutants on human health focuses on urban centers a... more Most research concerning the effects of air pollutants on human health focuses on urban centers and on the role of vehicular and industrial emissions as major sources of pollution. However, approxi ...
Science of The Total Environment
Children spend a significant amount of their day in preschool; thus, environmental quality at pre... more Children spend a significant amount of their day in preschool; thus, environmental quality at preschools may have an impact on children's health. In the present study, we analyzed polycyclic aromatic compounds (PACs), including PAHs, alkylated PAHs and oxygenated PAHs (OPAHs), in indoor and outdoor air particulate matter (PM10) and indoor dust at preschools in Stockholm, Sweden. There were significant correlations between PAC levels in outdoor and indoor PM10, with in general higher PAC levels outdoors. Fluoranthene and pyrene were detected at highest levels in all sample types, although phenanthrene and methylated phenanthrene derivatives also were found at high levels in indoor dust. In addition, the highly carcinogenic PAHs 7H-benzo[c]fluorene, 7,12-dimethylbenz[a]anthracene, benz[j]aceanthrylene, and dibenzo[a,l]pyrene were detected in some samples. Benzanthrone was the most prevalent OPAH in PM10 samples and 9,10-anthraquinone in indoor dust. Based on diagnostic ratios and Positive Matrix Factorization we identified vehicle emission and biomass burning as important PAC sources for all samples analyzed. However, poor correlation between PAC levels in indoor PM10 and indoor dust suggested additional sources for the latter. Measuring activation of DNA damage signaling in human cells exposed to organic extracts of the samples indicated substantial genotoxic potential of outdoor PM10 and indoor dust. Determination of benzo[a]pyrene equivalents demonstrated that the highly potent PAHs benz[j]aceanthrylene and dibenz[a,h]anthracene contributed more than 20% to the total carcinogenic potency of the samples. We conclude that PAC levels at Stockholm preschools are relatively low but that outdoor air quality may impact on the indoor environment.
Toxicology Letters
The Buccal Micronucleus Cytome Assay (BMCyt) has become an important biomonitoring tool for asses... more The Buccal Micronucleus Cytome Assay (BMCyt) has become an important biomonitoring tool for assessing cytogenetic damage in many studied populations. Each laboratory applies protocols that vary according to the method of collecting and preparing samples. Besides, Brazil is a country of great territorial extensions that received immigrants from various parts of the world with different genetic backgrounds. Therefore, the present study aimed to evaluate the inter-laboratory variation in scoring the same set of slides using the more comprehensive scoring criteria, to standardize the BMCyt protocol, to observe the basal alterations in populations of different Brazilian regions and to compare it with other places around the world. Our results showed that a valuable number of laboratories participated, ten laboratories from different regions of the country, for the validation of the BMCyt in human biomonitoring studies, resulting in the 804 healthy individuals. This was possible because we observed: a range of measures needs to be considered, such as the baseline frequency of DNA damage and cell death in non-exposed individuals; age when grouped showed an influence on DNA damage, although when evaluated by group we did not see an influence; association between smoking habit and all endpoints of the BMCyt (except karyolytic cells) was evident; the basal MN frequency, in the majority of groups, follows those around the world; and the BMCyt was confirmed as a good health status biomarker. We emphasize the need for constant discussions on the parameters of cell death due to greater difficulty among the analyzers.
Environmental Pollution
Approximately 3 billion people world-wide are exposed to air pollution from biomass burning. Here... more Approximately 3 billion people world-wide are exposed to air pollution from biomass burning. Herein, particulate matter (PM) emitted from artisanal cashew nut roasting, an important economic activity worldwide, was investigated. This study focused on: i) chemical characterization of polycyclic aromatic hydrocarbons (PAHs) and oxygenated (oxy-) PAHs; ii) intracellular levels of reactive oxygen species (ROS); iii) genotoxic effects and time- and dose-dependent activation of DNA damage signaling, and iv) differential expression of genes involved in xenobiotic metabolism, inflammation, cell cycle arrest and DNA repair, using A549 lung cells. Among the PAHs, chrysene, benzo[a]pyrene (B[a]P), benzo[b]fluoranthene, and benz[a]anthracene showed the highest concentrations (7.8-10 ng/m3), while benzanthrone and 9,10-anthraquinone were the most abundant oxy-PAHs. Testing of PM extracts was based on B[a]P equivalent doses (B[a]Peq). IC50 values for viability were 5.7 and 3.0 nM B[a]Peq at 24 h and 48 h, respectively. At these low doses, we observed a time- and dose-dependent increase in intracellular levels of ROS, genotoxicity (DNA strand breaks) and DNA damage signaling (phosphorylation of the protein checkpoint kinase 1 - Chk1). In comparison, effects of B[a]P alone was observed at micromolar range. To our knowledge, no previous study has demonstrated an activation of pChk1, a biomarker used to estimate the carcinogenic potency of PAHs in vitro, in lung cells exposed to cashew nut roasting extracts. Sustained induction of expression of several important stress response mediators of xenobiotic metabolism (CYP1A1, CYP1B1), ROS and pro-inflammatory response (IL-8, TNF-α, IL-2, COX2), and DNA damage response (CDKN1A and DDB2) was also identified. In conclusion, our data show high potency of cashew nut roasting PM to induce cellular stress including genotoxicity, and more potently when compared to B[a]P alone. Our study provides new data that will help elucidate the toxic effects of low-levels of PAH mixtures from air PM generated by cashew nut roasting.
Chemosphere
Retene (RET) is the most abundant polycyclic aromatic hydrocarbon (PAH) released upon burning of ... more Retene (RET) is the most abundant polycyclic aromatic hydrocarbon (PAH) released upon burning of cellulose, although it is not considered as one of the priority PAHs and is not included for risk assessments by the US Environmental Protection Agency (US-EPA). There are only a few studies concerning the toxic effects of RET. To the best of our knowledge, this study is the first one to examine whether RET, in an environmental concentration, plays a crucial role in the induction of oxidative stress in A549 lung cell line, and its consequence as such as mutagenicity and cell death. Our results revealed that RET was able to significantly decrease cell viability only at 72 h of exposure, increase oxidative stress, mitochondrial membrane potential and mitochondrial contents, leading an increased reactive oxygen species (ROS) production. Mutagenic activity was not detected in Salmonella strains, suggesting that RET does not induce base-pair substitution (TA100), frameshift (TA98 and TA97a) and transition/transversion (TA102) mutations. However, exposure to RET led to a significant increase in micronuclei (MN), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs) frequency, as well as cell death, mainly due to necrosis. Taken together, the results of our study provide new evidence suggesting that RET promotes oxidative stress, contributes to the processes of genomic instability, and favors necrosis. Thus, we highlight the importance of including RET in routine environmental analyses in the future as a potential risk factor involved in complex diseases and carcinogenesis.
Atmospheric Pollution Research
Abstract The ceramics manufacturing in northeastern Brazil has been dominated by archaic procedur... more Abstract The ceramics manufacturing in northeastern Brazil has been dominated by archaic procedures, in which the consumption of native wood extracted from the natural Caatinga biome is used as fuel in the process of clay burning. The aims of this study were to assess particulate matter (PM) physico-chemical characteristics and atmospheric modeling analyses, as well as the genotoxic potential using Tradescantia micronucleus assay associated to the emissions from the ceramic industry complex. The average PM concentration for all analyzed periods was 65 ± 26.2 μg m−3 for total suspended particles, and 23.4 ± 19.9 μg m−3 for PM10. Furthermore, the morphological analysis showed particles typical from biomass burning, such as soot carbon, spherical organic carbon and inorganic ash. The major elemental components were identified as Ba, Zn, Al, K, and Ca. Enrichment factor values showed that Ba and Zn were highly enriched in the ceramic production areas. Modeling analysis suggested that these particles can reach regions farther away from the emission sources. The frequency of micronuclei was 2.7–7.2 times higher than in the non-exposed area for all analyzed months. Moreover, a negative correlation between micronucleus and wind speed (r = −0.91; p = 0.04) was verified. This study addressed the effects of PM emitted from the ceramic industry on DNA damage and showed its genotoxic effects in meiotic cells despite the PM10 concentrations being within the upper WHO limits. The particulate air pollutants emitted from the wood burning by ceramics manufacturing are able to induce DNA damage in T. pallida, suggesting a required higher control of these air pollution emissions.
Environmental pollution (Barking, Essex : 1987), 2017
The present study is the first assessment of occupational risk associated with artisanal cashew n... more The present study is the first assessment of occupational risk associated with artisanal cashew nut roasting using exposure and effect biomarkers, as well as a characterization and dispersion analysis of the released particulate matter (PM). A real-time particle monitor was used to quantify PM1.0, PM2.5 and PM10. Furthermore, the PM was sampled using a Handi-vol sampler, and the physicochemical characteristics were determined by SEM-EDS analysis. Trajectories, dispersion and deposition of the emitted material were calculated using the NOAA-HYSPLIT model. Urinary 1-hydroxypyrene (1-OHP) levels were analyzed by HPLC. DNA damage, chromosomal instability and cell death were measured by a buccal micronucleus cytome assay (BMCyt). The PM concentrations for all measurements in the exposed area were higher than in the non-exposed area. SEM-EDS analyses exhibited a wide variety of particles, and K, Cl, S and Ca biomass burning tracers were the major inorganic compounds. In addition, atmosphe...
Toxicology Letters, 2016
The present study conducted the first assessment of the occupational risk associated to artisanal... more The present study conducted the first assessment of the occupational risk associated to artisanal cashew nut roasting by the use of exposure and effect biomarkers, as well as the characterization a ...
Vii Connepi Congresso Norte Nordeste De Pesquisa E Inovacao, Aug 20, 2012
Resumo: O Município de Itajá-RN destaca-se na microrregião do Vale do Açu como maior polo ceramis... more Resumo: O Município de Itajá-RN destaca-se na microrregião do Vale do Açu como maior polo ceramista. As cerâmicas são responsáveis pela produção de diversos materiais destinados à construção civil, dentre eles: tijolos, telhas e lajotas. Um total de 16 indústrias estão alojadas na cidade, produzindo em torno de 188,4 milhões de peças por ano e gerando 75% de empregos da população economicamente ativa local. A atividade ceramista promove deterioração da qualidade do ar, pois ela atua aumentando a quantidade de poluentes oriundos da queima da biomassa para abastecimento dos fornos. O objetivo deste estudo foi analisar o potencial genotóxico do ar de Itajá-RN através do teste de micronúcleo (MN) em Tradescantia pallida. O biomonitoramento foi realizado nos meses de março a junho de 2012. A análise citológica se deu pela contagem mensal do número de MN num grupo aleatório de 300 tétrades por lâmina. Os dados foram submetidos ao teste Mann-Whitney U e análise de correlação de Pearson. Para todos os meses analisados, foi verificado um aumento significativo (p < 0,01) nas frequências de MN quando comparado ao controle negativo. Foram verificadas uma correlação positiva (r = 0,86) entre a frequência de MN e a radiação solar e uma correlação negativa (r = -0,82) entre a frequência de MN e a velocidade dos ventos. Os resultados obtidos para a cidade de Itajá-RN indicaram que os elementos oriundos da queima de madeira para abastecimento dos fornos são capazes de elevar significativamente o número de MN em T. pallida, sugerindo um maior controle na emissão destes poluentes.
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Papers by Marcos Felipe de Oliveira Galvão