Environmental exposure to benzene: evaluation of urinary S-PMmorphism (CYP2E1-129A and poly3G>C and NQO1 609C> T) in Campos Elíseos residents, Duque de Caxias, Rio de Janeiro State, Brazil / Exposição ambiental ao benzeno: avaliação do S-PMA urinário e de polimorfismos (CYP2E1-1293G>C e NQO1 609C> T) em residentes de Campos Elíseos, Duque de Caxias, Rio de Janeiro, Brasil / Exposición ambiental al benceno: análisis del S-PMA en la orina y polimorfismo (CYP2E1-1293G>C y NQO1 609C> T) en residentes de Campos Elíseos, Duque de Caxias, Río de Janeiro, Brasil

Benzene is one of the most important substances for assessment, due to its significant use, the environmental contamination resulting from its emission and the effects on human health. It is classified by the International Agency for Research on Cancer (IARC) as a known carcinogen to humans (group 1) and associated with the development of leukemia. In general, the population is exposed to this substance by inhaling contaminated air, which varies according to the location and intensity of its potential sources. The petrochemical industry is one of the most important sources of this compound. The municipality of Duque de Caxias, specifically the Campos Elíseos district, in Rio de Janeiro State, Brazil, houses the Industrial Complex of Campos Elíseos (PICE), a grouping of over 25 industries, which includes the second largest oil refinery in Brazil. Environmental contamination from the PICE has been recognized, but there is a lack of studies concerning its impact on the health of the surrounding population. S-phenylmercapturic acid (S-PMA) concentrations ranging from 0.80 to 8.01μg.g-1 creatinine were observed in the local population, apparently related to hematological changes also observed in exposed population. The quantifiable presence of urinary S-PMA from the benzene metabolism is associated with the fact that 60% of the participants present specific hematological changes, which may be due to the environmental benzene exposure. The allele and genotype frequencies of the CYP2E1 and NQO1 enzymes observed in the study population were similar to those reported in other studies. The presence of the variant allele in the NQO1 genotype may be a risk factor for the observed hematological changes.

O benzeno é uma das substâncias mais importantes para a biomonitorização, em função do uso disseminado, da contaminação ambiental que resulta da emissão e dos efeitos sobre a saúde humana. O benzeno é classificado pela Agência Internacional de Pesquisa em Câncer (IARC) como carcinógeno conhecido em seres humanos (grupo 1) e está associado ao desenvolvimento de leucemias. Em geral, a população fica exposta a essa substância através da inalação do ar contaminado, que varia de acordo com a localização e a intensidade das fontes potenciais. A indústria petroquímica é uma das fontes mais importantes desse composto. O Município de Duque de Caxias, especificamente o Distrito de Campos Elíseos, no Estado do Rio de Janeiro, Brasil, é sede do Polo Industrial de Campos Elíseos (PICE), um conjunto de mais de 25 indústrias que inclui a segunda maior refinaria de petróleo no Brasil. A contaminação ambiental produzida pelo PICE já é conhecida, mas faltam estudos sobre o impacto na saúde da população local. Foram observadas concentrações de ácido S-fenilmercaptúrico (S-PMA) entre 0,80 e 8,01μg.g-1 creatinina na população local, aparentemente implicadas nas alterações hematológicas também observadas na população exposta. A presença quantificável do S-PMA urinário do metabolismo do benzeno está associada ao fato de 60% dos participantes apresentarem alterações hematológicas específicas, o que pode ser devido à exposição ambiental ao benzeno. As frequências alélicas e genotípicas das enzimas CYP2E1 e NQO1, observadas na população do estudo, foram semelhantes àquelas relatadas em outros estudos. A presença da variante alélica do genótipo NQO1 pode ser um fator de risco para as alterações hematológicas observadas.

El benceno es una de las sustancias más importantes susceptibles de estudio, debido a su uso significativo, la contaminación ambiental resultante de sus emisiones y sus efectos sobre la salud humana. Está clasificado por el Centro Internacional de Investigaciones sobre el Cáncer (IARC) como un conocido carcinógeno para los humanos (grupo 1) y está asociado con el desarrollo de leucemias. En general, la población está expuesta a esta sustancia por inhalación de aire contaminado, que varía según el lugar y la intensidad de las emisiones. La industria petroquímica es un de las fuentes emisoras más importantes de este compuesto. La municipalidad de Duque de Caxias, específicamente el distrito de Campos Elíseos, en Río de Janeiro, Brasil, alberga el Complejo Industrial de Campos Elíseos (PICE), un conglomerado de más de 25 industrias, que incluye la segunda mayor refinería de petróleo en Brasil. La contaminación ambiental procedente del PICE ya ha sido reconocida, pero es notable la falta de estudios respecto a su impacto en la salud de la población circundante. Se observaron en la población local concentraciones de ácido s-fenilmercaptúrico (SPMA por sus siglas en inglés) que oscilan entre los 0,80 a 8,01μg.g-1 creatinina, aparentemente relacionadas con cambios hematológicos también hallados en la población expuesta. La presencia cuantificable de SPMA en la orina, procedente del metabolismo del benceno, está asociada con el hecho de que un 60% de los participantes presenta cambios específicos hematológicos, los cuales tal vez se deben a la exposición ambiental al benceno. Las frecuencias alélicas y genotípicas del CYP2E1 y enzimas NQO1 observadas en el estudio fueron similares a las reportadas en otros estudios. La presencia de la variante alélica en el genotipo NQO1 podría ser un factor de riesgo para los cambios hematológicos observados.

Assessment of ocular surface toxicity after topical instillation of nitric oxide donors / Avaliação da toxicidade na superfície ocular após instilação tópica de doadores de óxido nítrico

PURPOSE: To evaluate the ocular surface toxicity of two nitric oxide donors in ex vivo and in vivo animal models: S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylcysteine (SNAC) in a hydroxypropyl methylcellulose (HPMC) matrix at final concentrations 1.0 and 10.0 mM. METHODS: Ex vivo GSNO and SNAC toxicities were clinically and histologically analyzed using freshly excised pig eyeballs. In vivo experiments were performed with 20 albino rabbits which were randomized into 4 groups (5 animals each): Groups 1 and 2 received instillations of 150 µL of aqueous HPMC solution containing GSNO 1.0 and 10.0 mM, respectively, in one of the eyes; Groups 3 and 4 received instillations of 150 µL of aqueous HPMC solution-containing SNAC 1.0 and 10.0 mM, respectively, in one of the eyes. The contralateral eyes in each group received aqueous HPMC as a control. All animals underwent clinical evaluation on a slit lamp and the eyes were scored according to a modified Draize eye test and were histologically analyzed. RESULTS: Pig eyeballs showed no signs of perforation, erosion, corneal opacity or other gross damage. These findings were confirmed by histological analysis. There was no difference between control and treated rabbit eyes according to the Draize eye test score in all groups (p>0.05). All formulations showed a mean score under 1 and were classified as "non-irritating". There was no evidence of tissue toxicity in the histological analysis in all animals. CONCLUSION: Aqueous HPMC solutions containing GSNO and SNAC at concentrations up to 10.0 mM do not induce ocular irritation.

OBJETIVO: Avaliar a toxidade na superfície ocular de dois compostos doadores de óxido nítrico em modelos ex vivo e in vivo: S-nitrosoglutationa (GSNO) e S-nitroso-N-acetilcisteína (SNAC), em uma matriz de hidroxipropil metilcelulose (HPMC) nas concentrações finais de 1,0 and 10,0 mM. MÉTODOS: As toxicidades de GSNO e SNAC foram avaliadas clinicamente e histologicamente em modelo ex vivo usando globos oculares porcinos recém excisados. Experimentos in vivo foram realizados com 20 coelhos albinos que foram randomizados em 4 grupos (5 animais em cada): Os grupos 1 e 2 receberam instilações de 150 µL de solução aquosa de HPMC contendo GSNO 1,0 e 10,0 mM, respectivamente, em um dos olhos; Os grupos 3 e 4 receberam instilações de 150 µL de solução aquosa de HPMC contendo SNAC 1,0 and 10,0 mM, respectivamente, em um dos olhos. Os olhos contralaterias em cada grupo receberam solução aquosa de HPMC como controle. Todos os animais foram clinicamente avaliados em lâmpada de fenda e os olhos foram pontuados de acordo com o teste de Draize modificado e analisados histologicamente. RESULTADOS: Os globos oculares porcinos não apresentaram sinais de perfuração, erosão, opacidade da córnea ou outros danos graves. Esses resultados foram confirmados pela análise histológica. Não houve diferença entre os olhos dos coelhos tratados e controles de acordo com a pontuação do teste de Draize em todos os grupos (p>0,05). Todas as formulações apresentaram um escore médio menor do que 1 e foram classificadas como "não-irritantes". Não houve evidência de toxicidade tecidual nas análises histológicas em todos os animais. CONCLUSÃO: Soluções aquosas de HPMC contendo GSNO e SNAC em concentrações até 10,0 mM não induzem irritação ocular.

S-nitroso-N-acetylcysteine ameliorates ischemia-reperfusion injury in the steatotic liver

BACKGROUND: Steatosis is currently the most common chronic liver disease and it can aggravate ischemia-reperfusion (IR) lesions. We hypothesized that S-nitroso-N-acetylcysteine (SNAC), an NO donor component, can ameliorate cell damage from IR injury. In this paper, we report the effect of SNAC on liver IR in rats with normal livers compared to those with steatotic livers. METHODS: Thirty-four rats were divided into five groups: I (n=8), IR in normal liver; II (n=8), IR in normal liver with SNAC; III (n=9), IR in steatotic liver; IV (n=9), IR in steatotic liver with SNAC; and V (n=10), SHAN. Liver steatosis was achieved by administration of a protein-free diet. A SNAC solution was infused intraperitoneally for one hour, beginning 30 min. after partial (70 percent) liver ischemia. The volume of solution infused was 1 ml/100 g body weight. The animals were sacrificed four hours after reperfusion, and the liver and lung were removed for analysis. We assessed hepatic histology, mitochondrial respiration, oxidative stress (MDA), and pulmonary myeloperoxidase. RESULTS: All groups showed significant alterations compared with the group that received SHAN. The results from the steatotic SNAC group revealed a significant improvement in liver mitochondrial respiration and oxidative stress compared to the steatotic group without SNAC. No difference in myeloperoxidase was observed. Histological analysis revealed no difference between the non-steatotic groups. However, the SNAC groups showed less intraparenchymal hemorrhage than groups without SNAC (p=0.02). CONCLUSION: This study suggests that SNAC effectively protects against IR injury in the steatotic liver but not in the normal liver.

A novel thiol compound, N-acetylcysteine amide, attenuates allergic airway disease by regulating activation of NF-kappaB and hypoxia-inducible factor-1alpha

Reactive oxygen species (ROS) play an important role in the pathogenesis of airway inflammation and hyperresponsiveness. Recent studies have demonstrated that antioxidants are able to reduce airway inflammation and hyperreactivity in animal models of allergic airway disease. A newly developed antioxidant, small molecular weight thiol compound, N-acetylcysteine amide (AD4) has been shown to increase cellular levels of glutathione and to attenuate oxidative stress related disorders such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. However, the effects of AD4 on allergic airway disease such as asthma are unknown. We used ovalbumin (OVA)-inhaled mice to evaluate the role of AD4 in allergic airway disease. In this study with OVA-inhaled mice, the increased ROS generation, the increased levels of Th2 cytokines and VEGF, the increased vascular permeability, the increased mucus production, and the increased airway resistance in the lungs were significantly reduced by the administration of AD4. We also found that the administration of AD4 decreased the increases of the NF-kappaB and hypoxia-inducible factor-1alpha (HIF-1alpha) levels in nuclear protein extracts of lung tissues after OVA inhalation. These results suggest that AD4 attenuates airway inflammation and hyperresponsiveness by regulating activation of NF-kappaB and HIF-1alpha as well as reducing ROS generation in allergic airway disease.

Evaluation of benzene exposure in adults and urinary s-phenylmercapturic acid in children living in Adelaide, South Australia

Benzene Exposure was evaluated in adults and children living in Adelaide, South Australia by measuring benzene and urinary s-phenylmercapturic acid [SPMA]. To determine of benzene exposure in each subject the personal passive samplers was used and samples were analyzed by gas chromatography system equipped to flame ionization detector. The level of SPMA was determined by competitive enzymelinked immunosorbent assay [ELISA] in children. The mean concentration of benzene in Summer and Winter were 1.62 +/- 1.43 and 1.36 +/- 0.87 ppb respectively. There was a significant difference between exposure to benzene for subjects with less and more than 6 hours activity over days of week [p<0.05]. The mean urinary concentrations levels of SPMA adjusted to creatinene for children that living less and more than 200 meters mol/mol creatinene, respectively and distance from main road were 1.56 and 4.67 the significant difference was seen in two groups [p<0.005]. Data shows, that SPMA can be utilized as a biomarker for exposure to benzene in children. Exposure to benzene is more for children that living near to main road compare to other children. Adults have more activity in out side of home has more exposure to benzene than other people

Simultaneous determination of trans, transmuconic acid and s-phenylmercapturic acid by high pressure liquid chromatography and its application.

The simultaneous determination of urinary trans,trans-muconic acid (t,t-MA) and S-phenylmercapturic acid (S-PMA) was performed by liquid extraction with ethyl acetate and reversed-phase high performance liquid chromatography (RP-HPLC) on a Hypersil-ODS column using the gradient mobile phase of methanol and 0.0012 N perchloric acid and diode array detection at 205 and 264 nm for S-PMA and t,t-MA, respectively. The retention times for t,t-MA and S-PMA were 3.8 and 12.3 minutes, respectively. The recoveries of t,t-MA and S-PMA were > 97%; between-day precisions were all within 8% RSD (100x SD/mean). The method was applied to analyze the urinary t,t-MA and S-PMA of 59 service station attendants exposed to average benzene concentrations in the air of 0.20+/-0.18 ppm. Significant differences in pre-shift and post-shift urinary t,t-MA between smokers and non-smokers were found.

Partial purification of protein farnesyl cysteine carboxyl methyltransferase from bovine brain

C-terminal farnesyl cysteine carboxyl methylation has been known to be the last step in the post-translational modification processes of several important signal transduction proteins in eukaryotes including ras related GTP binding proteins and the gamma-subunit of heterotrimeric G proteins. Protein farnesyl cysteine carboxyl methyltransferase (PFCCMT; EC, 2.1.1.100) catalyzing the reaction is well characterized as being stimulated by guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) and suppressed by N-acetyl-S-farnesyl-L-cysteine (AFC). As an initial step to understand the physiological significance of the process, we attempted to purify the enzyme, which was partially purified 130-fold (specific activity, 143 pmol of methyl group transferred/min/mg of protein) with yield of 1.8% after purification by fast protein liquid chromatography (FPLC) on a Superdex 75 column. The enzyme was further purified with non denaturing polyacrylamide gel electrophoresis (ND-PAGE) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight of PFCCMT was determined to be about 30 kDa based on Superdex 75 FPLC as well as photoaffinity labelling with S-adenosyl-L-[methyl-3H] methionine ([methyl-3H]SAM). The partially purified enzyme (Superdex 75 eluate) was found to be characteristically affected by GTP gamma S, being activated about 40-fold in 2 mM, in contrast to ATP which did not show any effect on enzyme activity. Meanwhile, the enzyme was found to be markedly inhibited by AFC, reaching 0 activity in 2 mM. These observations strongly suggested that the partially purified enzyme was PFCCMT.