ABSTRACT
Tolerance to Polycyclic Hydrocarbons Aromatic (PAHs) is considered an important characteristic when assessing the bioremediation potential of microorganisms. Given this, the objective of this research was to assay filamentous fungi from the Amazon region, isolated from sediments with differents levels of contamination by PAHs, for tolerance to phenanthrene and pyrene. To achieve this, fungal cultures plugs (5 mm), obtained after 7 days growth, were transferred to petri dishes containing 20% Sabouraud dextrose agar medium, after surface innoculation with phenanthrene and pyrene crystals, separately. Radial mycelial growth was evaluated after 10 days at five different concentration levels for each contaminant and control group, all in triplicate for each treatment. Fungal growth and growth inhibition rates were calculated. The average growth of the colonies in each treatment was compared with one-way ANOVA, followed by a Tukey Test (p 0,05). All fungi showed tolerant to phenanthrene and pyrene. However, Hypoxylon sp. showed the lowest growth inhibition rate and average growth rates significantly different of the other six tested species. Hypoxylon sp. has been shown to be a promising genetic resource for use in new studies of PAHs degradation.(AU)
A tolerância a Hidrocarbonetos Policíclicos Aromática (HPAs) é considerada como umacaracterística importante na avaliação do potencial de micro-organismos para biorremediação. Diante disso,o objetivo desta pesquisa foi avaliar fungos filamentosos da região amazônica, isolados de sedimentos comdiferentes níveis de contaminação por HPAs, quanto à tolerância ao fenantreno e pireno. Para tanto, discosdas culturas fúngicas (5 mm), obtidas após 7 dias de crescimento, foram transferidas para placas de Petricontendo meio Agar Sabouraud Dextrose a 20%, após inoculação superficial com cristais de fenantreno epireno, separadamente. O crescimento micelial radial foi avaliado após 10 dias em cinco concentraçõesdiferentes para cada contaminante e grupo controle, ambos em triplicata para cada tratamento. As taxas decrescimento fúngico e de inibição de crescimento foram calculadas. O crescimento médio das colônias emcada tratamento foi comparado com ANOVA one way, seguido pelo teste de Tukey (p < 0,05). Todos osfungos mostraram tolerância ao fenantreno e ao pireno. No entanto, Hypoxylon sp. apresentou menor taxade inibição de crescimento e taxas médias de crescimento significativamente diferentes das outras seisespécies testadas. Hypoxylon sp. tem se mostrado um recurso genético promissor para uso em novos estudossobre degradação de HPAs.(AU)
Subject(s)
Polycyclic Aromatic Hydrocarbons/administration & dosage , Fungi/chemistry , Geologic Sediments/analysisABSTRACT
Polycyclic aromatic hydrocarbons are known carcinogens used in rodent experimental models. In this study, the carcinogen DMBA (7,12-dimethylbenzanthracene) was administered by gavage, diluted in corn oil, to female BALB / c mice at hebdomadary doses of 1 mg per animal for 1, 3, 6 or 9 weeks. Animals were weighed and monitored weekly until death. Remaining animals were euthanized at the age of 53 weeks. At necropsy, representative fragments of neoplasms were collected and routinely processed for histopathological analysis. Of all mice that received DMBA, 68.57% developed some type of tumor. Of the 70 mice treated with various doses of DMBA, 22 (31.43%) developed mammary tumors. The adenoacanthoma was the most commonly (18.75%) diagnosed histological type of breast cancer. Lung (15.71%), lymphoid tissue (11.43%), stomach (7.14%) and skin (2.86%) were also primary sites of tumor development. One third (33.33%) of the mice receiving 1 mg of DMBA developed lung cancer. Therefore, the administration of DMBA was shown to be an efficient model of carcinogenesis in mice, especially for the study of breast cancer, when using the highest dose, and lung, when using the lowest dose. Carcinogenesis models have been used for several purposes in cancer research. These results represent new facts for a classic carcinogenesis model.
Hidrocarbonetos policíclicos e aromáticos são carcinógenos usados em modelos experimentais em roedores. Neste estudo, o carcinógeno DMBA (7,12-dimetilbenzantraceno) foi administrado por gavagem, diluído em óleo de milho, para camundongos BALB/c em doses hebdomadárias de 1 mg por animal por 1, 3, 6 ou 9 semanas. Os animais foram pesados e monitorados semanalmente até a morte. Os animais remanescentes foram eutanasiados com a idade de 53 semanas. Na necroscopia, fragmentos representativos das neoplasias foram colhidos e rotineiramente processados para exame histopatológico. De todos os animais que receberam DMBA, 68,57% desenvolveram algum tipo de tumor. Entre os 70 camundongos tratados com diferentes doses de DMBA, 22 (31,43%) desenvolveram neoplasias mamárias. O adenoacantoma foi o tumor mamário mais comumente diagnosticado (18,75%). Pulmões (15,71%), tecido linfoide (11,43%), estômago (7,14%) e pele (2,86%) foram também locais primários de desenvolvimento de neoplasias. Um terço (33,33%) dos camundongos que receberam 1 mg de DMBA desenvolveram neoplasias pulmonares. Portanto, a administração de DMBA foi considerada um modelo eficiente de carcinogênese em camundongos, especialmente para o estudo de neoplasias mamárias, quando a maior dose é utilizada, e de neoplasias pulmonares, quando utilizada a menor dose. Os modelos de carcinogênese química têm sido usados para diversos estudos na pesquisa em câncer, os resultados aqui apresentados mostram novos fatos para um modelo clássico de carcinogênese.
Subject(s)
Animals , Mice , /administration & dosage , Carcinogenesis/chemically induced , Mammary Neoplasms, Experimental/chemically induced , Rats, Inbred Strains/immunology , Polycyclic Aromatic Hydrocarbons/administration & dosage , Neoplasms/veterinaryABSTRACT
Polycyclic aromatic hydrocarbons are known carcinogens used in rodent experimental models. In this study, the carcinogen DMBA (7,12-dimethylbenzanthracene) was administered by gavage, diluted in corn oil, to female BALB / c mice at hebdomadary doses of 1 mg per animal for 1, 3, 6 or 9 weeks. Animals were weighed and monitored weekly until death. Remaining animals were euthanized at the age of 53 weeks. At necropsy, representative fragments of neoplasms were collected and routinely processed for histopathological analysis. Of all mice that received DMBA, 68.57% developed some type of tumor. Of the 70 mice treated with various doses of DMBA, 22 (31.43%) developed mammary tumors. The adenoacanthoma was the most commonly (18.75%) diagnosed histological type of breast cancer. Lung (15.71%), lymphoid tissue (11.43%), stomach (7.14%) and skin (2.86%) were also primary sites of tumor development. One third (33.33%) of the mice receiving 1 mg of DMBA developed lung cancer. Therefore, the administration of DMBA was shown to be an efficient model of carcinogenesis in mice, especially for the study of breast cancer, when using the highest dose, and lung, when using the lowest dose. Carcinogenesis models have been used for several purposes in cancer research. These results represent new facts for a classic carcinogenesis model. (AU)
Hidrocarbonetos policíclicos e aromáticos são carcinógenos usados em modelos experimentais em roedores. Neste estudo, o carcinógeno DMBA (7,12-dimetilbenzantraceno) foi administrado por gavagem, diluído em óleo de milho, para camundongos BALB/c em doses hebdomadárias de 1 mg por animal por 1, 3, 6 ou 9 semanas. Os animais foram pesados e monitorados semanalmente até a morte. Os animais remanescentes foram eutanasiados com a idade de 53 semanas. Na necroscopia, fragmentos representativos das neoplasias foram colhidos e rotineiramente processados para exame histopatológico. De todos os animais que receberam DMBA, 68,57% desenvolveram algum tipo de tumor. Entre os 70 camundongos tratados com diferentes doses de DMBA, 22 (31,43%) desenvolveram neoplasias mamárias. O adenoacantoma foi o tumor mamário mais comumente diagnosticado (18,75%). Pulmões (15,71%), tecido linfoide (11,43%), estômago (7,14%) e pele (2,86%) foram também locais primários de desenvolvimento de neoplasias. Um terço (33,33%) dos camundongos que receberam 1 mg de DMBA desenvolveram neoplasias pulmonares. Portanto, a administração de DMBA foi considerada um modelo eficiente de carcinogênese em camundongos, especialmente para o estudo de neoplasias mamárias, quando a maior dose é utilizada, e de neoplasias pulmonares, quando utilizada a menor dose. Os modelos de carcinogênese química têm sido usados para diversos estudos na pesquisa em câncer, os resultados aqui apresentados mostram novos fatos para um modelo clássico de carcinogênese. (AU)
Subject(s)
Animals , Mice , Rats, Inbred Strains/immunology , 9,10-Dimethyl-1,2-benzanthracene/administration & dosage , Carcinogenesis/chemically induced , Mammary Neoplasms, Experimental/chemically induced , Polycyclic Aromatic Hydrocarbons/administration & dosage , Neoplasms/veterinaryABSTRACT
PRIMARY OBJECTIVE: To develop of a quantitative food frequency questionnaire (QFFQ) to assess intake of specific foods, nutrients and heterocyclic aromatic amines (HAAs) in a case-control study of colorectal adenoma. METHODS AND PROCEDURES: A cross-sectional survey conducted in a hospital in Sao Paulo, Brazil. A trained dietitian collected 24-h recalls from 60 Japanese Brazilian outpatients (29 men and 31 women; mean age 58 years and 57 years, respectively). MAIN OUTCOMES AND RESULTS: Fruit, vegetable and legume intake was high, with mean daily servings consumed in men and women of 8.2 and 6.9, respectively. The QFFQ contains 161 food items presented in 15 food groupings, with particular emphasis paid to the HAA content of meat, fish and chicken items. CONCLUSIONS: We have developed a QFFQ appropriate for Japanese Brazilians that will allow us to estimate HAA intake and will be used to examine our hypotheses related to foods, nutrients and HAAs, and diet-gene interactions in colorectal neoplasia in this population.