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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Frequência de micronúcleos em células esfoliadas da mucosa bucal de pacientes obesos / Micronuclei frequency in exfoliated buccal cells of obese patients

Carvalho, Cristiane Alves Paz de 29 June 2012 (has links)
A crescente incidência da obesidade e suas comorbidades constituem-se em um grande desafio para a saúde no mundo. Além da doença cardiovascular e do diabetes, dados epidemiológicos demonstraram ligação entre a obesidade e diversos tipos de câncer. As alterações citogenéticas tem sido utilizadas como biomarcadores para identificação de danos celulares. Este estudo teve como objetivos: comparar a frequência dos tipos celulares (células basais e diferenciadas), anormalidades nucleares (células binucleadas, picnóticas, cariorréticas, cariolíticas e com cromatina condensada) e de danos celulares (micronúcleos e brotos nucleares) de células bucais esfoliadas em um grupo de obesos (teste) e em um grupo de indivíduos com peso normal (controle). A amostra foi composta por 30 indivíduos, sendo o grupo teste constituído por indivíduos obesos mórbidos (n=15) e o grupo controle por indivíduos com peso normal (n=15). A classificação do peso corporal foi feita de acordo com o Índice de Massa Corporal (IMC); um questionário forneceu informações sobre exposições ocupacionais e não ocupacionais; hábitos e dieta. As células da mucosa bucal foram coletadas da mucosa jugal, de ambos os lados, processadas e analisadas microscopicamente. Para cada indivíduo foram avaliadas 1000 células para a caracterização dos tipos celulares (basal e diferenciada) e alterações nucleares (células binucleadas, picnose, cariólise, cariorrexe, cromatina condensada) e 2000 células diferenciadas para verificar a presença de danos celulares (micronúcleos e brotos nucleares). Os dados foram processados e analisados estatisticamente, por meio do teste de Mann Whitney. Considerou-se o nível de significância de 5% (p<0,05). Observaram-se diferenças nas frequências de tipos celulares e anomalias nucleares para os dois grupos, porém estas diferenças não foram significativas (p>0,05). Quanto ao tipo de dano celular, notou-se a mesma frequência de brotos nucleares para ambos os grupos, entretanto, a frequência de micronúcleos foi maior para o grupo obeso (p<0,001). Neste estudo, verificou-se maior frequência de micronúcleos nas células esfoliadas da mucosa bucal em indivíduos obesos mórbidos que em indivíduos com peso normal. Este achado sugere que a obesidade possa levar à maior ocorrência de alterações citogenéticas. / The increasing incidence of obesity and its co-morbid conditions poses a great challenge to global health. In addition to cardiovascular disease and diabetes, epidemiological data demonstrate a link between obesity and multiple types of cancer. The buccal micronucleus cytome assay has been used as a biomarker for identification of cell damage. This study aimed to compare the frequency of cell types (basal and differentiated), nuclear anomalies (binucleated, pyknotic, karyorrhectic, karyolitic and condensed chromatin cells), and cell damage (micronuclei and nuclear buds) in exfoliated buccal cells in a group of obese (test) and a group of normal weight (control).The sample consisted of 30 subjects, the test group comprised of individuals with morbid obesity (n = 15) and a control group of normal weight (n = 15). The classification of body weight was made according to Body Mass Index (BMI), a questionnaire provided information on occupational exposures and non-occupational, lifestyle and diet. The oral mucosa cells were collected from the buccal mucosa, on both sides, processed and analyzed microscopically. For each individual 1000 cells were evaluated for the characterization of cell types (basal and differentiated) and nuclear abnormalities (binucleated cells, pyknosis, karyolysis, karyorrhexis, condensed chromatin) and 2000 differentiated cells for the presence of cellular damage (micronuclei and nuclear buds). The data were processed and statistically analyzed using the Mann-Whitney test. We considered the significance level of 5% (p <0.05). Differences were observed in the frequencies of cell types and nuclear abnormalities in both groups, but these differences were not significant (p> 0.05). Regarding the type of cell damage, we noticed the same frequency of nuclear buds for both groups, however, the frequency of micronuclei was higher in the obese group (p <0.001). In this study, there was a higher frequency of micronuclei in exfoliated cells of buccal mucosa in morbidly obese individuals than in individuals with normal weight. This finding suggests that obesity may lead to higher rates of cytogenetic changes.
2

Frequência de micronúcleos em células esfoliadas da mucosa bucal de pacientes obesos / Micronuclei frequency in exfoliated buccal cells of obese patients

Cristiane Alves Paz de Carvalho 29 June 2012 (has links)
A crescente incidência da obesidade e suas comorbidades constituem-se em um grande desafio para a saúde no mundo. Além da doença cardiovascular e do diabetes, dados epidemiológicos demonstraram ligação entre a obesidade e diversos tipos de câncer. As alterações citogenéticas tem sido utilizadas como biomarcadores para identificação de danos celulares. Este estudo teve como objetivos: comparar a frequência dos tipos celulares (células basais e diferenciadas), anormalidades nucleares (células binucleadas, picnóticas, cariorréticas, cariolíticas e com cromatina condensada) e de danos celulares (micronúcleos e brotos nucleares) de células bucais esfoliadas em um grupo de obesos (teste) e em um grupo de indivíduos com peso normal (controle). A amostra foi composta por 30 indivíduos, sendo o grupo teste constituído por indivíduos obesos mórbidos (n=15) e o grupo controle por indivíduos com peso normal (n=15). A classificação do peso corporal foi feita de acordo com o Índice de Massa Corporal (IMC); um questionário forneceu informações sobre exposições ocupacionais e não ocupacionais; hábitos e dieta. As células da mucosa bucal foram coletadas da mucosa jugal, de ambos os lados, processadas e analisadas microscopicamente. Para cada indivíduo foram avaliadas 1000 células para a caracterização dos tipos celulares (basal e diferenciada) e alterações nucleares (células binucleadas, picnose, cariólise, cariorrexe, cromatina condensada) e 2000 células diferenciadas para verificar a presença de danos celulares (micronúcleos e brotos nucleares). Os dados foram processados e analisados estatisticamente, por meio do teste de Mann Whitney. Considerou-se o nível de significância de 5% (p<0,05). Observaram-se diferenças nas frequências de tipos celulares e anomalias nucleares para os dois grupos, porém estas diferenças não foram significativas (p>0,05). Quanto ao tipo de dano celular, notou-se a mesma frequência de brotos nucleares para ambos os grupos, entretanto, a frequência de micronúcleos foi maior para o grupo obeso (p<0,001). Neste estudo, verificou-se maior frequência de micronúcleos nas células esfoliadas da mucosa bucal em indivíduos obesos mórbidos que em indivíduos com peso normal. Este achado sugere que a obesidade possa levar à maior ocorrência de alterações citogenéticas. / The increasing incidence of obesity and its co-morbid conditions poses a great challenge to global health. In addition to cardiovascular disease and diabetes, epidemiological data demonstrate a link between obesity and multiple types of cancer. The buccal micronucleus cytome assay has been used as a biomarker for identification of cell damage. This study aimed to compare the frequency of cell types (basal and differentiated), nuclear anomalies (binucleated, pyknotic, karyorrhectic, karyolitic and condensed chromatin cells), and cell damage (micronuclei and nuclear buds) in exfoliated buccal cells in a group of obese (test) and a group of normal weight (control).The sample consisted of 30 subjects, the test group comprised of individuals with morbid obesity (n = 15) and a control group of normal weight (n = 15). The classification of body weight was made according to Body Mass Index (BMI), a questionnaire provided information on occupational exposures and non-occupational, lifestyle and diet. The oral mucosa cells were collected from the buccal mucosa, on both sides, processed and analyzed microscopically. For each individual 1000 cells were evaluated for the characterization of cell types (basal and differentiated) and nuclear abnormalities (binucleated cells, pyknosis, karyolysis, karyorrhexis, condensed chromatin) and 2000 differentiated cells for the presence of cellular damage (micronuclei and nuclear buds). The data were processed and statistically analyzed using the Mann-Whitney test. We considered the significance level of 5% (p <0.05). Differences were observed in the frequencies of cell types and nuclear abnormalities in both groups, but these differences were not significant (p> 0.05). Regarding the type of cell damage, we noticed the same frequency of nuclear buds for both groups, however, the frequency of micronuclei was higher in the obese group (p <0.001). In this study, there was a higher frequency of micronuclei in exfoliated cells of buccal mucosa in morbidly obese individuals than in individuals with normal weight. This finding suggests that obesity may lead to higher rates of cytogenetic changes.
3

Forensic DNA collection: extraction of molecular information from buccal cells using direct amplification

Brochu, Elizabeth Anne 01 November 2017 (has links)
Reference samples are a vital part of the forensic analysis of deoxyribonucleic acid (DNA) evidence. Efficient processing and analysis of these sample types are required for comparative analysis of an unknown electropherogram (EPG) and forensic databasing purposes (12). These reference samples can be derived from blood swabs or cheek swabs, the latter also being known as buccal cell swabs (20, 22, 32). Buccal cells, or epithelial cells of the oral cavity, are the preferred cell type for known samples as their collection is non-invasive and painless (20-21). Buccal cell collection devices typically consist of a swab (cotton or foam) and a filter paper, commonly FTA paper (1). FTA paper contains proprietary chemicals that lyse cell membranes upon contact, trapping and stabilizing DNA for downstream processing (21, 34). FTA paper also inhibits bacterial and viral growth and protects against damage from UV radiation, nucleases and oxidation (21, 34). Some of the benefits of using FTA cards include the ability to store the cards at ambient temperature for years (21, 35, 37) and to perform direct amplification of the samples thereby removing the need to utilize DNA extraction and quantitative polymerase chain reaction (qPCR) (32, 37, 39). The EasiCollectTM (EC) and EasiCollectTM + (EC+) Buccal Sample Collection Devices (General Electric (GE) Healthcare Life Sciences, Buckinghamshire, UK) have FTA sample collection cards that contain a proprietary dye that changes color from pink to white, indicating where colorless fluids, such as saliva, were likely deposited (42). This study consisted of four phases. Phase 0 determined the optimal amplification conditions, including number of polymerase chain reaction (PCR) cycles and an appropriate capillary electrophoresis (CE) injection time for high template, single source samples obtained from FTA cards using the EC and EC+ buccal cell collection devices. Samples were obtained from EC FTA cards with a Harris 1.2-mm Uni-Core Punch and amplified using the GlobalfilerTM Express PCR Amplification Kit (Thermo Fisher Scientific, Waltham, MA) using the manufacturer’s protocol with 26, 27 or 28 PCR cycles (28). Fragment separation was achieved on an ABI 3500 Genetic Analyzer (Applied Biosystems, Foster City, CA) with 5, 15 and 25 second (s) 1.2 kiloVolt (kV) injections. Samples were analyzed on GeneMapper® ID-X v1.4 (Applied Biosystems, Foster City, CA) with an analytical threshold of 150 RFU (relative fluorescence units) (31). It was determined that amplification with 26 PCR cycles was optimal for high template, single source samples from FTA cards in this laboratory. The three injection times were utilized in the remaining phases and no other parameters were changed. In Phase 1 of this study, the optimal collection method for the EC+ device from various processes was assessed using the following collection variables: 1) a dry or saliva-wet swab; 2) a circular or up-down/side-to-side motion; 3) 2, 3 or 4 motions; and 4) swabbing of one or both cheeks. This resulted in a total of 24 distinct collection processes. We found that collection techniques that involved wetting the foam head of the EC+ device provided higher peak heights, improved heterozygote balance (Hb) and minimized the rate of drop-out in EPGs. When swabbing two cheeks versus one, the median peak heights increased, indicating an increase in transfer of cellular material onto the FTA surface. The motion of swabbing - circular or up-down/side-to-side - did not have an effect on the overall quality of the EPG data. During Phase 2a, the distribution of cellular material was assessed for two collection processes that involved swabbing of two cheeks with a wet swab four times; the variation among the methods being the motion (circular or up-down/side-to-side). Two punches taken surrounding the original punch assessed during Phase 1 showed similar average peak heights (i.e. ca. 3500 RFU at a 5 s injection on the ABI 3500 Genetic Analyzer) for both collection processes. No allelic drop-out was observed with either collection technique. Phase 2b compared the EPG signal of the EC and EC+ collection devices. The EC+ collection process used for this comparison involved rubbing a wet swab across two cheeks using four circular motions as this produced no allelic drop-out and fewer samples which saturated the CE laser detector. Therefore, this method provided more data for analysis. Samples from both devices produced comparable peak heights and PHRs above 0.6 with no allelic drop-out and stutter ratios below the thresholds set by the manufacturer (28). The EC+ device was found to be robust and provided full profiles using a minimalist sample collection method. However, the probability of drop-out increased as both the number of motions and the number of cheeks decreased. Based on this study, a collection using four circular motions divided between two cheeks with a wet swab is recommended with a 5 s, 1.2 kV injection on an ABI 3500 Genetic Analyzer, since full DNA profiles were obtained with balanced heterozygote loci, expected stutter ratios, and acceptable levels of minus A artifact. Further, it was determined that this recommended collection method resulted in high-fidelity DNA signal for up to three punches. Thus, the EC+ device is reliable, easy-to-use and non-invasive for the collection of buccal cells for known reference samples. A sample obtained from the area of transfer on an FTA card from the EC+ device can produce an EPG of the quality required for the comparison of known samples to an evidentiary profile as well as for input of the genotype into a national forensic database.
4

Avaliação dos constituintes e do potencial mutagênico do material particulado oriundo do beneficiamento artesanal da castanha do caju / Assessment of the components and mutagenic potential of particulate matter from artisanal cashew nut roasting

Cabral, Thiago de Melo 08 June 2010 (has links)
DA CASTANHA DE CAJU Apesar da importância social e econômica do beneficiamento da castanha de caju para o Rio Grande do Norte, a produção ainda é realizada de forma artesanal. Para a coleta da amêndoa da castanha é necessário assá-la. A fumaça gerada durante a queima da castanha possui altas concentrações de Material Particulado (MP) e esse MP produzido é inalado diariamente por grupos familiares por um período que pode exceder a 10 horas diárias. Em geral, os poluentes atmosféricos oriundos da queima de biomassa são potencialmente nocivos a saúde, relacionando-se com eventos de genotoxicidade, aumento no número de internações hospitalares e ambulatoriais, e mortalidade por doenças cardiovasculares e respiratórias. O presente trabalho teve três objetivos principais: 1° Realizar medições na concentração de O3, NO2, MP, Black Carbon (BC) e composição elementar do MP 2,5 provenientes da queima da castanha. 2° Identificar o potencial mutagênico associado ao beneficiamento artesanal da castanha de caju durante a estação seca, chuvosa e intermediária no RN (Brasil) com o auxílio do teste de micronúcleo (MN) em Tradescantia pallida. 3° Verificar o efeito mutagênico da atividade em MN de células esfoliadas de mucosa oral de trabalhadores envolvidos no beneficiamento. Para isso, três locais distintos foram definidos como pontos testes: Ponto 1. Comunidade do Amarelão, situada no perímetro rural do município de João Câmara-RN (local onde ocorre a queima da castanha de caju); Ponto 2. Fazenda Santa Luzia, situada próxima à região de queima da castanha de caju (local com as mesma condições ambientais do Ponto 1, porém sem a influência da atividade); Ponto 3. Universidade Federal do Rio Grande do Norte (UFRN), zona urbana de Natal-RN. Os resultados obtidos para o O3 e NO2 não excederam os limites estabelecidos pela legislação brasileira. No entanto, os resultados da medição de MP obtidos com o medidor portátil \"DUSTTRAK (TM)Aerossol Monitor \" indicou que entre as 8 medições de MP realizadas no Ponto 1, 7 excederam o nível de exposição definido como \"estado de emergência \"descrito na legislação brasileira (500µg/m 3 ), diferindo significativamente dos resultados obtidos nos Pontos 2 e 3 (6µg/m 3 ). As avaliações realizadas nos meses de Janeiro, Maio e Setembro de 2009, com o Mini-sampler confirmaram os resultados previamente obtidos com o \"DUSTTRAK (TM)Aerossol Monitor \".O valor médio de MP 2,5 (Jan - 548,412 µg/m 3 ; Mai - 1022,232 µg/m 3 ; Set - 1291,946 µg/m 3 ) e BC (Jan - 46,798 µg/m 3 ; Mai 70,068- µg/m 3 ; Set - 69,432 µg/m 3 ) obtido nas três campanhas para o Ponto 1 foram significativamente maiores que o Ponto 2 e 3. Para o Ponto 1 os elementos Si, S, Cl, K, Ni, Cu e Zn quando presentes estiveram em concentrações superiores aos Pontos 2 e 3. Os testes de genotoxicidade com T. pallida indicou aumento significativo no número de MN em todas as campanhas. Os resultados com células de mucosa oral humana corroboraram com o biomonitor vegetal, sendo verificado aumento significativo na freqüência de MN. Os resultados obtidos caracterizaram um dos piores níveis de exposição humana ao MP já relatado na literatura, excedendo amplamente os limites da legislação brasileira assim como os da OMS. Os resultados obtidos apresentaram um problema ocupacional grave, sendo necessária intervenção imediata dos gestores públicos na tentativa de minimizar os efeitos lesivos da atividade. / x Despite the social and economic importance of the processing of cashew nuts to Rio Grande do Norte, the production is still carried out artisanally. To collect the almond nut is necessary to roasting. The smoke generated during the burning of the nut has high concentrations of particulate matter (PM) and the PM produced is inhaled daily by families for a period which can exceed 10 hours a day. In general, air pollutants come from burning biomass are potentially harmful to health, relating to genotoxicity events, increase in the number of hospitalizations and outpatient, and mortality from cardiovascular and respiratory diseases. This project had three main objectives: 1 Make measurements in the concentration of O3, NO2, MP, Black Carbon (BC) and elemental composition of the PM 2.5 from the combustion of the cashew nut. 2 Identify the mutagenic potential associated with artisanally processing of cashew nut during the dry season, wet and intermediate in RN (Brazil) by using a micronucleus (MN) bioassay of T. pallida tetrads. 3 To investigate the effect of mutagenic activity in exfoliated cells of oral mucosa of workers involved in processing. For this, three test sites were chosen for this purpose: Site 1. the Amarelão community - where the roasting occurs, Site 2. the Santa Luzia farm - an area near the roasting site, though without direct influence on the process and Site 3. the Universidade Federal do Rio Grande do Norte (UFRN) - an urban area of Natal, Brazil. The results obtained for the O3 and NO2 do not exceed the limits established by Brazilian legislation. However, the results of the measurement of PM obtained with the portable meter \"DUSTTRAK (TM) Aerosol Monitor\" has indicated that between 8 PM measurements made at Site 1, 7 exceeded the level of exposure defined as \"emergency rule\" described in the Brazilian legislation (500 ? g/m 3 ), differing significantly from the results obtained in Sites 2 and 3 (6 ? g/m 3 ). Evaluations in January, May and September 2009, with the Mini-sampler confirmed the results previously obtained with the \"DUSTTRAK (TM)Aerosol Monitor.The average value of 2.5 MP (Jan - 548.412 mg/m 3 ; May - 1022.232 mg/m 3 ; Set - 1291.946 mg/m 3 ) and BC (Jan - 46.798 mg/m 3 ; May 70.068 - mg/m 3 ; Set - 69.432 mg/m 3 ) obtained in the three campaigns for Site 1 were significantly higher than the Site 2 and 3. To the Site 1 the elements Si, S, Cl, K, Ni, Cu and Zn when present were at concentrations higher than the Sites 2 and 3. Genotoxicity tests with T. pallida showed a significant increase in the number of MN in all campaigns. The results with cells of human oral mucosa have confirmed the biomonitoring, and found significant increase in the frequency of MN. The results marked one of the worst levels of human exposure to PM has been reported in the literature and greatly exceeded the limits of the Brazilian legislation as well as the WHO. The results showed a serious occupational problem, requiring immediate intervention of public officials in an attempt to minimize the harmful effects of the activity.
5

Avaliação dos constituintes e do potencial mutagênico do material particulado oriundo do beneficiamento artesanal da castanha do caju / Assessment of the components and mutagenic potential of particulate matter from artisanal cashew nut roasting

Thiago de Melo Cabral 08 June 2010 (has links)
DA CASTANHA DE CAJU Apesar da importância social e econômica do beneficiamento da castanha de caju para o Rio Grande do Norte, a produção ainda é realizada de forma artesanal. Para a coleta da amêndoa da castanha é necessário assá-la. A fumaça gerada durante a queima da castanha possui altas concentrações de Material Particulado (MP) e esse MP produzido é inalado diariamente por grupos familiares por um período que pode exceder a 10 horas diárias. Em geral, os poluentes atmosféricos oriundos da queima de biomassa são potencialmente nocivos a saúde, relacionando-se com eventos de genotoxicidade, aumento no número de internações hospitalares e ambulatoriais, e mortalidade por doenças cardiovasculares e respiratórias. O presente trabalho teve três objetivos principais: 1° Realizar medições na concentração de O3, NO2, MP, Black Carbon (BC) e composição elementar do MP 2,5 provenientes da queima da castanha. 2° Identificar o potencial mutagênico associado ao beneficiamento artesanal da castanha de caju durante a estação seca, chuvosa e intermediária no RN (Brasil) com o auxílio do teste de micronúcleo (MN) em Tradescantia pallida. 3° Verificar o efeito mutagênico da atividade em MN de células esfoliadas de mucosa oral de trabalhadores envolvidos no beneficiamento. Para isso, três locais distintos foram definidos como pontos testes: Ponto 1. Comunidade do Amarelão, situada no perímetro rural do município de João Câmara-RN (local onde ocorre a queima da castanha de caju); Ponto 2. Fazenda Santa Luzia, situada próxima à região de queima da castanha de caju (local com as mesma condições ambientais do Ponto 1, porém sem a influência da atividade); Ponto 3. Universidade Federal do Rio Grande do Norte (UFRN), zona urbana de Natal-RN. Os resultados obtidos para o O3 e NO2 não excederam os limites estabelecidos pela legislação brasileira. No entanto, os resultados da medição de MP obtidos com o medidor portátil \"DUSTTRAK (TM)Aerossol Monitor \" indicou que entre as 8 medições de MP realizadas no Ponto 1, 7 excederam o nível de exposição definido como \"estado de emergência \"descrito na legislação brasileira (500µg/m 3 ), diferindo significativamente dos resultados obtidos nos Pontos 2 e 3 (6µg/m 3 ). As avaliações realizadas nos meses de Janeiro, Maio e Setembro de 2009, com o Mini-sampler confirmaram os resultados previamente obtidos com o \"DUSTTRAK (TM)Aerossol Monitor \".O valor médio de MP 2,5 (Jan - 548,412 µg/m 3 ; Mai - 1022,232 µg/m 3 ; Set - 1291,946 µg/m 3 ) e BC (Jan - 46,798 µg/m 3 ; Mai 70,068- µg/m 3 ; Set - 69,432 µg/m 3 ) obtido nas três campanhas para o Ponto 1 foram significativamente maiores que o Ponto 2 e 3. Para o Ponto 1 os elementos Si, S, Cl, K, Ni, Cu e Zn quando presentes estiveram em concentrações superiores aos Pontos 2 e 3. Os testes de genotoxicidade com T. pallida indicou aumento significativo no número de MN em todas as campanhas. Os resultados com células de mucosa oral humana corroboraram com o biomonitor vegetal, sendo verificado aumento significativo na freqüência de MN. Os resultados obtidos caracterizaram um dos piores níveis de exposição humana ao MP já relatado na literatura, excedendo amplamente os limites da legislação brasileira assim como os da OMS. Os resultados obtidos apresentaram um problema ocupacional grave, sendo necessária intervenção imediata dos gestores públicos na tentativa de minimizar os efeitos lesivos da atividade. / x Despite the social and economic importance of the processing of cashew nuts to Rio Grande do Norte, the production is still carried out artisanally. To collect the almond nut is necessary to roasting. The smoke generated during the burning of the nut has high concentrations of particulate matter (PM) and the PM produced is inhaled daily by families for a period which can exceed 10 hours a day. In general, air pollutants come from burning biomass are potentially harmful to health, relating to genotoxicity events, increase in the number of hospitalizations and outpatient, and mortality from cardiovascular and respiratory diseases. This project had three main objectives: 1 Make measurements in the concentration of O3, NO2, MP, Black Carbon (BC) and elemental composition of the PM 2.5 from the combustion of the cashew nut. 2 Identify the mutagenic potential associated with artisanally processing of cashew nut during the dry season, wet and intermediate in RN (Brazil) by using a micronucleus (MN) bioassay of T. pallida tetrads. 3 To investigate the effect of mutagenic activity in exfoliated cells of oral mucosa of workers involved in processing. For this, three test sites were chosen for this purpose: Site 1. the Amarelão community - where the roasting occurs, Site 2. the Santa Luzia farm - an area near the roasting site, though without direct influence on the process and Site 3. the Universidade Federal do Rio Grande do Norte (UFRN) - an urban area of Natal, Brazil. The results obtained for the O3 and NO2 do not exceed the limits established by Brazilian legislation. However, the results of the measurement of PM obtained with the portable meter \"DUSTTRAK (TM) Aerosol Monitor\" has indicated that between 8 PM measurements made at Site 1, 7 exceeded the level of exposure defined as \"emergency rule\" described in the Brazilian legislation (500 ? g/m 3 ), differing significantly from the results obtained in Sites 2 and 3 (6 ? g/m 3 ). Evaluations in January, May and September 2009, with the Mini-sampler confirmed the results previously obtained with the \"DUSTTRAK (TM)Aerosol Monitor.The average value of 2.5 MP (Jan - 548.412 mg/m 3 ; May - 1022.232 mg/m 3 ; Set - 1291.946 mg/m 3 ) and BC (Jan - 46.798 mg/m 3 ; May 70.068 - mg/m 3 ; Set - 69.432 mg/m 3 ) obtained in the three campaigns for Site 1 were significantly higher than the Site 2 and 3. To the Site 1 the elements Si, S, Cl, K, Ni, Cu and Zn when present were at concentrations higher than the Sites 2 and 3. Genotoxicity tests with T. pallida showed a significant increase in the number of MN in all campaigns. The results with cells of human oral mucosa have confirmed the biomonitoring, and found significant increase in the frequency of MN. The results marked one of the worst levels of human exposure to PM has been reported in the literature and greatly exceeded the limits of the Brazilian legislation as well as the WHO. The results showed a serious occupational problem, requiring immediate intervention of public officials in an attempt to minimize the harmful effects of the activity.
6

Biomarkers of oxidative stress and DNA damage in agricultural workers

Muniz, Juan Fermin 15 December 2009 (has links)
Pesticides are among the most pervasive environmental contaminants and they are an important potential risk for human health. Agricultural workers are constantly exposed to pesticide spray, drift and residues in the soil and foliage. Many agricultural pesticides are readily absorbed by the body, through contact with the skin, the respiratory track, the eyes, and the gastrointestinal system. Multiple studies have reported a strong association between pesticide exposure and various health outcomes including cancer. Oxidative stress and DNA damage have been proposed as mechanisms linking pesticide exposure to health effects and neurological diseases. The focus of the present translational study is to examine the relationship between human exposure to the organophosphate pesticide azinphos methyl (AZM) and oxidative stress by measuring biomarkers of oxidative stress in biological fluids (i.e., urine, serum) and peripheral blood lymphocytes (PBLs) of agricultural workers. The findings from these field studies will be validated in vitro by examining cultures of human lymphocytes treated with AZM for similar biomarkers of oxidative stress. Since the collection of PBLs from study participants is highly invasive and not suitable for studies involving younger subjects, we also examined buccal cells for biomarkers of oxidative stress (i.e., DNA damage) as a more universal source of human tissue to assess oxidative stress in pesticide exposed individuals. We demonstrated in this study that AZM induces oxidative stress and causes DNA damage in human tissues. Agricultural workers who had been exposed to AZM showed elevated serum levels of lipid peroxides, increased urinary levels of 8-OH-dG, and lymphocytes from these individuals showed increased DNA damage and associated changes in oxidative DNA repair enzymes. Biomarkers of oxidative stress were also elevated in human lymphocytes treated with physiologically relevant concentrations of AZM. In cultures of human lymphocytes, AZM caused a concentration-dependent loss of viability and associated increases in ROS and a reduction in intracellular GSH. We also demonstrated that viable leukocytes from the oral cavity can be readily obtained from humans and these buccal cells can be used to assess DNA damage following exposure to occupational and environmental genotoxicants. We also noted that oral leukocytes are especially sensitive to cryopreservation with DMSO and thus, these cells must be cryoprotected with 5% DMSO to preserve the viability of these cells for subsequent biochemical studies. In summary, these in vivo and in vitro studies demonstrated that AZM induces oxidative stress in a dose-dependent matter and that oral lymphocytes are a good source of human tissue for assessing DNA damage and possibly other biochemical changes. The possible health implications of the variations in these biomarkers of oxidative stress and DNA damage are undetermined. Yet the findings from these studies have provided a strong foundation for determining the mechanism by which pesticide induce oxidative stress, to explore the putative relationship between pesticide-induced oxidative stress and disease (e.g. cancer, neurodegenerative disorders) and determine whether tissue damage in humans is brought about by direct or by indirect action of organophosphate pesticides. / Graduation date: 2010

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