Effects of physical exercise training in DNA damage and repair - could the difference be in hOGG1 Ser326Cys polymorphism?

Acute physical exercise is associated with increased oxygen consumption, which could result in an increased formation of reactive oxygen species (ROS). ROS can react with several organic structures, namely DNA, causing strand breaks and a variety of modified bases in DNA. Physical exercise training seems to decrease the incidence of oxidative stress-associated diseases, and is considered as a key component of a healthy lifestyle. This is a result of exercise-induced adaptation, which has been associated with the possible increase in antioxidant activity and in oxidative damage repair enzymes, leading to an improved physiological function and enhanced resistance to oxidative stress (Radak et al. 2008). Human 8-oxoguanine DNA glycosylase 1 (hOGG1) is involved in the base excision repair (BER) pathway and encodes an enzyme responsible for removing the most common product of oxidative damage in DNA, 8-hydroxyguanine (8-OH-G). The genetic polymorphism of hOGG1 at codon 326 results in a serine (Ser) to cysteine (Cys) amino acid substitution (Ser326Cys). It has been suggested that the carriers of at least one hOGG1Cys variant allele exhibit lower 8-OH-G excision activity than the wild-type (Wilson et al. 2011). The aim of this study was to investigate the possible influence of hOGG1 Ser326Cys polymorphism on DNA damage and repair activity in response to 16 weeks of combined physical exercise training, in thirty healthy Caucasian men. Comet assay was carried out using peripheral blood lymphocytes and enabled the evaluation of DNA damage, both strand breaks and FPG-sensitive sites, and DNA repair activity. Genotypes were determined by PCR-RFLP analysis. The subjects with Ser/Ser genotype were considered as wild-type group (n=20), Ser/Cys and Cys/Cys genotype were analyzed together as mutant group (n=10). Regarding differences between pre and post-training in the wild-type group, the results showed a significant decrease in DNA strand breaks (DNA SBs) (p=0.002) and also in FPG-sensitive sites (p=0.017). No significant differences were observed in weight (p=0.389) and in lipid peroxidation (MDA) (p=0.102). A significant increase in total antioxidant capacity (evaluated by ABTS) was observed (p=0.010). Regarding mutant group, the results showed a significant decrease in DNA SBs (p=0.008) and in weight (p=0.028). No significant differences were observed in FPG-sensitive sites (p=0.916), in ABTS (p=0.074) and in MDA (p=0.086). No significant changes in DNA repair activity were observed in both genotype groups. This preliminary study suggests the possibility of different responses in DNA damage to physical exercise training, considering the hOGG1 Ser326Cys polymorphism.

Exposure assessment: the influence of environmental monitoring methodology

Exposure assessment is an important step of risk assessment process and has evolved more quickly than perhaps any aspect of the four-step risk paradigm (hazard identification, exposure assessment, dose-response analysis, and risk characterization). Nevertheless, some epidemiological studies have associated adverse health effects to a chemical exposure with an inadequate or absent exposure quantification. In addition to the metric used, the truly representation of exposure by measurements depends on: the strategy of sampling, random collection of measurements, and similarity between the measured and unmeasured exposure groups. Two environmental monitoring methodologies for formaldehyde occupational exposure were used to assess the influence of metric selection in exposure assessment and, consequently, in risk assessment process.

In vitro toxicity screening of silica-coated superparamagnetic iron oxide nanoparticles in glial cells

Nanotechnology industry is progressing with prospects of substantial benefits to economics and science. Superparamagnetic iron oxide nanoparticles (ION) have been showing excellent magnetic properties, biocompatibility and biodegradability, broadening their potential applications and importance in the biomedical field

Ventilation influence in occupational exposure to fungi and volatile organic compounds: poultry case

Introduction - In poultry houses, large-scale production has led to increased bird densities within buildings. Such high densities of animals kept within confined spaces are a source of human health problems related to occupational organic dust exposure. This organic dust is composed of both non-viable particles and viable particulate matter (also called bioaerosols). Bioaerosols are comprised by airborne bacteria, fungi, viruses and their by-products, endotoxins and mycotoxins. Exposure to fungi in broiler houses may vary depending upon the applied ventilation system. Ventilation can be an important resource in order to reduce air contamination in these type of settings. Nevertheless, some concerns regarding costs, sensitivity of the animal species to temperature differences, and also the type of building used define which type of ventilation is used. Aim of the study - A descriptive study was developed in one poultry unit aiming to assess occupational fungal and volatile organic compounds (VOCs) exposure.

Air fungal contamination in ten hospitals’ food units from Lisbon

A descriptive study was developed to monitor air fungal contamination in ten food units from hospitals. Fifty air samples of 250 litres were collected through impaction method. Samples were collected in food storage facilities, kitchen, food plating, canteen and also, outside premises, since this is the place regarded as reference. Simultaneously, environmental parameters were also monitored, including temperature and relative humidity through the equipment Babouc, LSI Sistems and according to the International Standard ISO 7726.

Avaliação da força de preensão em indivíduos expostos e não expostos a actividade manual específica (repetitividade e exposição ao frio): estudo comparativo

A função básica da mão humana consiste na preensão dos vários objectos em todas as actividades quotidianas, incluindo a actividade laboral. Esta é grandemente influenciada pela força e pela destreza manuais. O objectivo geral deste estudo foi comparar a força de preensão global da mão em trabalhadores com actividade laboral de características especificamente manuais em relação à população sem actividade manual específica. Considerámos pertinente a realização deste estudo como contributo para a avaliação das alterações da força de preensão da mão com repercussões ao nível da sua funcionalidade. O estudo realizado é do tipo descritivo, quase experimental e de desenho transversal. Para o efeito, seleccionou-se por conveniência uma amostra de 125 participantes dos quais 50 formaram o Grupo de Estudo, tratando-se de trabalhadores que utilizam instrumentos manuais de corte e que se encontram expostos a desenvolver tarefas repetitivas em ambiente frio. Os restantes 75 participantes formaram o Grupo de Controlo não expostos às condições referidas.

Desigualdades na mortalidade, espaço e estratos sociais

OBJETIVO: Descrever os diferenciais da mortalidade do Município de Salvador, Bahia, Brasil. MÉTODOS: Foi realizado estudo de agregados a partir da divisão do município em 75 zonas de informação e de sua população em seis estratos sociais para os quais foram estimados alguns indicadores de mortalidade. As fontes de dados foram as Declarações de Óbito de residentes no município e o Censo Demográfico de 1991. RESULTADOS: A diferença entre os coeficientes de mortalidade do estrato com melhores condições de vida e aqueles com piores condições de vida variou entre 43,1% e 142,0% o que corresponde a Razões de Desigualdades de 1,4 e 2,4. Essas diferenças atingiram percentuais de 656,3% quando a unidade de análise foi a zona de informação. CONCLUSÕES: Esses achados revelam a persistência das desigualdades em saúde no Brasil, destacando a importância desse tipo de análise diante das tendências recentes de planificação com base territorial bem como diante da pertinência de intervenções inter-setoriais voltadas para a modificação dos fatores condicionantes da saúde.

Occupational exposure to aflatoxin (AFB1) in poultry production

Aflatoxin B1 (AFB1) has been recognized to cause cancer in the humans liver. Epidemiological and laboratory evidence also point towards the respiratory system as target for carcinogenesis. Exposure occurs mainly through food chain but inhalation represent an additional route of exposure. Agricultural workers have the greatest risk of occupational exposure due to their exposition to airborne aflatoxin through inhalation of dust.

Fungal contamination of poultries litter: a public health problem

Exposure to certain fungi can cause human illness. Fungi cause adverse human health effects through three specific mechanisms: generation of a harmful immune response (e.g., allergy or hypersensitivity pneumonitis); direct infection by the fungal organism; by toxic-irritant effects from mold byproducts, such as mycotoxins. In Portugal there is an increasingly industry of large facilities that produce whole chickens for domestic consumption and only few investigations have reported on fungal contamination of the poultry litter. The material used for poultry litter is varied but normally can be constitute by: pine shavings; sawdust of eucalyptus; other types of wood; peanut; coffee; sugar cane; straw; hay; grass; paper processed. Litter is one of the most contributive factors to fungal contamination in poultries. Spreading litter is one of the tasks that normally involve higher exposure of the poultry workers to dust, fungi and their metabolites, such as VOC’s and mycotoxins. After being used and removed from poultries, litter is ploughed into agricultural soils, being this practice potentially dangerous for the soil environment, as well for both humans and animals. The goal of this study was to characterize litter’s fungal contamination and also to report the incidence of keratinophilic and toxigenic fungi.

Perfil da demanda atendida em ambulatório de doenças profissionais e a presença de lesões por esforços repetitivos

OBJETIVO: Caracterizar o perfil do paciente atendido em ambulatório de doenças profissionais de um hospital geral e, em especial, o portador da condição patológica mais freqüente: as lesões por esforços repetitivos (LER). MÉTODOS: Foram analisadas as 565 fichas-resumo de atendimento ambulatorial em saúde do trabalhador, em 1996, em função de variáveis sociodemográficas, de características do trabalho e de diagnóstico. Foram adotados os seguintes procedimentos: descrição univariável de todas as variáveis; análise bivariada, utilizando-se o teste do qui-quadrado (chi²) para variáveis categóricas; comparação de médias ou amplitudes para variável categórica e outra quantitativa; análise multivariada por meio de modelos log-linear, com transformação logit, para detectar os grupos com maior proporção de LER. RESULTADOS: Houve predomínio no atendimento de pacientes do sexo feminino com menos de 40 anos, sendo que, nos casos de LER, esse predomínio mostrou-se mais acentuado. As ocupações agrupadas apareceram em ordem decrescente, na seqüência: administrativos, operários e prestadores de serviços, sendo 59,6% pertencentes ao ramo de atividade econômica de serviços. As LER corresponderam a 56% dos diagnósticos feitos nas primeiras consultas. CONCLUSÕES: Confirmou-se a tendência de mudança no perfil epidemiológico das demandas atendidas no ambulatório de doenças profissionais, no final da década de 80, quando emergiram as LER. Deslocaram-se para uma minoria as antigas doenças profissionais decorrentes da exposição a riscos químicos e físicos, em função daquelas relacionadas às condições ergonômicas inadequadas.

Genotoxic effects of exposure to formaldehyde in two different occupational settings

Formaldehyde (CH2O), the most simple and reactive aldehyde, is a colorless, reactive and readily polymerizing gas at room temperature (National Toxicology Program [NTP]. It has a pungent suffocating odor that is recognized by most human subjects at concentrations below 1 ppm. Aleksandr Butlerov synthesized the chemical in 1859, but it was August Wilhelm von Hofmann who identified it as the product formed from passing methanol and air over a heated platinum spiral in 1867. This method is still the basis for the industrial production of formaldehyde today, in which methanol is oxidized using a metal catalyst. By the early 20th century, with the explosion of knowledge in chemistry and physics, coupled with demands for more innovative synthetic products, the scene was set for the birth of a new material–plastics. According to the Report on Carcinogens, formaldehyde ranks 25th in the overall U.S. chemical production, with more than 5 million tons produced each year. Formaldehyde annual production rises up to 21 million tons worldwide and it has increased in China with 7.5 million tons produced in 2007. Given its economic importance and widespread use, many people are exposed to formaldehyde environmentally and/or occupationally. Commercially, formaldehyde is manufactured as an aqueous solution called formalin, usually containing 37% by weight of dissolved formaldehyde. This chemical is present in all regions of the atmosphere arising from the oxidation of biogenic and anthropogenic hydrocarbons. Formaldehyde concentration levels range typically from 2 to 45 ppbV (parts per billion in a given volume) in urban settings that are mainly governed by primary emissions and secondary formation.

Prevalência de sintomas de lesões músculo-esqueléticas ligadas ao trabalho: contributos para a intervenção centrada no trabalhador

Mestrado em Intervenção Sócio-Organizacional na Saúde - Área de especialização: Qualidade e Tecnologias da Saúde.

Contributo para a validação de uma estratégia de diagnóstico do risco de LMELT: empresas de triagem de resíduos orgânicos

Mestrado em Segurança e Higiene no Trabalho.

Contributo da análise ergonómica do trabalho para o estudo de acidentes de trabalho em enfermeiros no serviço de urgência

Mestrado em Segurança e Higiene no Trabalho.